2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015, 2014, 2013, 2012, 2011, 2010, 2009, 2008, 2007, 2006, 2005, 2004, 2003, 2002, 2001, 2000, 1999, 1998, and 1997
Seminars in 2023
Wednesday December 13 2023 at 3:30pm in DRL 2C8
Bernd Surrow – Temple University
Status of the U.S.-based Electron-Ion Collider Project
Understanding the properties of nuclear matter and its emergence through the underlying partonic
structure and dynamics of quarks and gluons requires a new experimental facility in hadronic
physics known as the Electron-Ion Collider (EIC). The EIC will address some of the most profound
questions concerning the emergence of nuclear properties by precisely imaging gluons and quarks
inside protons and nuclei, such as the distribution of gluons and quarks in space and momentum,
their role in building the nucleon spin, and the properties of gluons in nuclei at high energies. A
new detector collaboration has been formed around one of two possible interaction regions, the
ePIC collaboration. This presentation will discuss the overall status and plans of the EIC project,
focusing primarily on the EIC physics program and the ePIC detector design.
Wednesday November 1 2023 at 3:30pm in DRL 2C8
Ian Dyckes – LBNL
The mystery of cold noise in ATLAS upgrade silicon strip modules
In preparation for the High Luminosity LHC, the ATLAS Experiment is constructing a new Inner Tracker (ITk) composed of silicon pixel and silicon strip detectors. After multiple years of prototyping, the ITk strips community entered the pre-production phase in late-2021. However, in early 2022, clusters of channels exceeding the noise specification were observed when testing modules at the design operating temperature of -35C. This observation of “Cold Noise” interrupted pre-production and initiated an extensive investigation into the cause and potential mitigation strategies. This talk will summarize our current understanding of the Cold Noise mechanism, highlighting the most insightful studies from this year-long investigation.
Wednesday October 18 2023 at 3:30pm in DRL 2C8
Elena Villhauer – University of Edinburgh
Defying 4D Gravity: Novel searches for signatures of string theory via scalar cascades, noncommutative black holes, non-minimal dark sectors, and deep learning
The existence of extra dimensions could lower the fundamental Planck scale to the low TeV scale and very excitingly allow string theory to be probed at the LHC. This talk introduces novel searches for signatures of string theory via three models that have never been searched for by any experiment: scalar cascades, noncommutative black holes, and non-minimal dark sectors. Deep learning is employed through the use of particle flow networks to learn jet substructure and design analysis regions. The background estimation is automated through the implementation of distance correlation in the neural network loss function. A novel jet reclustering algorithm is used to overcome the challenges associated with a soft final state. Future directions are also discussed.
Wednesday April 5 2023 at 10:45 am in DRL 4N12
Chris Hays – Oxford
High-precision measurement of the W boson mass with the CDF II detector
The mass of the W boson, a mediator of the weak force between elementary particles, is tightly constrained by the symmetries of the standard model of particle physics. We have performed the most precise measurement of the W boson mass using data corresponding to 8.8 inverse femtobarns of integrated luminosity collected in proton-antiproton collisions at 1.96 TeV center-of-mass energy with the CDF II detector at the Fermilab Tevatron collider. The measured value is in significant tension with the prediction.
Link to paper in Science
Wednesday March 22 2023 at 3:30pm in 2C8
Scott Thomas – Rutgers
New Physics Frontiers at the Large Hadron Collider
Thursday March 16 2023 at 11am in 4N9
Nathaniel Craig – UC Santa Barbara
Naturalness
Wednesday February 15 2023 at 3:30pm in 2C8
Maxim Pospelov (University of Minnesota)
Electric Dipole Moments: review and recent developments
The search for EDMs is one of the most motivated low-energy searches for New Physics that violates CP. I review the main mechanisms that convert fundamental CP-violating parameters of the SM (theta_QCD and Kobayashi-Maskawa phase) to the observable electric dipole moments (EDMs). In light of recent experimental progress, the EDMs connected to electron spin (paramagnetic EDMs) are calculated. The limit on QCD theta angle is 3 * 10^(-8) and somewhat subdominant to neutron EDM, but can be further improved. The Kobayashi-Maskawa phase contributes to paramagnetic EDMs at the level of 10^{-35} e cm in units of equivalent electron EDM, which is three orders of magnitude larger than what was previously estimated.
Wednesday January 25 2023 at 3:30pm in 2C8
Prachi Arvind Atmasiddha – University of Michigan
Observation of the Radiation Amplitude Zero Effect and the first
measurement of longitudinal-longitudinal diboson polarization fractions
using WZ events in high-pT phase space
In the standard model of particle physics, the spontaneous symmetry breaking of the complex
Higgs field gives rise to the massive Higgs boson and three Goldstone bosons. These Goldstone
bosons become the longitudinal components of the W and Z bosons. It is critical to study the
longitudinal-longitudinal interactions of two bosons. In this talk, I will present the first
measurement of different diboson polarization fractions using WZ fully-leptonic events (WZ →
lvll) in the W_0 Z_0-enhanced region with 139 fb-1 of data taken by the ATLAS detector at
√s =13 TeV. A non-zero longitudinal-longitudinal polarization fraction is expected to be
observed with more than 5 sigma sensitivity. The Radiation Amplitude Zero effect in WZ events
helps to reduce the transversal-transversal polarization fraction. Along with high-pT^Z selection,
this effect also increases the sensitivity of the longitudinal-longitudinal polarization fraction
measurement. I will present the first observation of the Radiation Amplitude Zero effect in WZ
events. I will also describe my contribution to the ATLAS New Small Wheel detector integration,
commissioning and test beam performance studies.
Thursday January 12 2023 at 11:15am in 3W2 (TBC)
Dr Shion Chen (Tokyo)
Quest for dark matter from the high-energy & low-temperature frontiers
While the cosmological properties of dark matter has been very well-established,
the lack of our knowledge about its mass puts us in a situation of searching a mass range of >10^30 order of magnitude difference in the direct detection program.
From the heavy side, the WIMP dark matter in GeV-TeV has been the most theoretically motivated candidate e.g. by SUSY,
and the direct production in the energy frontier collider is one of the most effective probes.
On the light end, bosonic wave-like dark matter is viable below eV, realized by e.g. axion(-like particles) or dark photon.
The search experiments particularly gain wider attention lately because of the advancement of cryogenic and quantum technologies driven by the rise of superconducting quantum computers.
This seminar will discuss the recent results of the SUSY dark matter searches in LHC/ATLAS – which just started to show its real potential with the full Run2 data statistics – as well as the haloscope experiments targeting axions and dark photon, with a particular focus on the potential leap achieved by the introduction of superconducting qubits in the future.
Wednesday January 11 2023 at 3:30pm in 2C8
Dr Jeff Dandoy (Penn)
Novel Searches for Electroweak Supersymmetry and the ATLAS HL-LHC Upgrade of the Silicon Strip Detector
There are several observed phenomena incompatible with the Standard Model of particle physics, including dark matter and the light mass of the Higgs boson. Recent hints of additional anomalies have brought increased motivation to search for Electroweak Supersymmetry at the LHC. Several new results from the ATLAS Collaboration are presented targeting models with both R-parity conserving and violating decays into three-lepton final states as well as prospects for future searches including new final states. The High Luminosity upgrades of the LHC and the ATLAS experiment will greatly expand our ability to produce and detect rare new physics processes but presents unique challenges from a busy, high-radiation environment. Recent developments in the design and testing of the upgraded readout electronics of the charged-particle tracking silicon strip detector are discussed.
Seminars in 2022
Wednesday August 31 at 3:30pm in 2C8
Professor Michelle Dolinski (Drexel)
EXO-200 recent results and nEXO outlook
The discovery of neutrino mass is direct evidence of physics beyond the Standard Model.
It is an experimentally open question whether neutrinos have Majorana masses, and neutrinoless double beta decay is the most promising experimental technique to search for Majorana neutrinos. EXO-200 and nEXO are part of a program to search for neutrinoless double beta decay of Xe-136 using single phase liquid xenon time projection chamber technology. I will report on recent results from the EXO-200 experiment, which ran from 2011 to 2018 at the Waste Isolation Pilot Plant in Carlsbad, NM. I will also discuss technical progress toward nEXO, a next generation experiment with a projected 10-year half-life sensitivity of 1.35×1028 yr at 90% confidence level.
Wednesday September 28 at 3:30pm in 3W2 (Joint Experimental/Theoretical)
Dr Johannes Michel (MIT)
Precision Physics & Proton Structure at the LHC
The LHC precision program critically relies on precise theory predictions for Standard-Model baseline rates to identify possible deviations due to New Physics and extract Standard Model parameters like the W mass. In this talk, I will present third-order QCD predictions for Higgs, Z, and W boson production at the LHC, with a particular focus on their transverse-momentum (qT) distributions, and including fully realistic fiducial acceptance cuts on their decay products. I will discuss how the resummation of large logarithms of qT, which is governed by the factorization of the cross section in terms of transverse-momentum dependent (TMD) PDFs, gives rise to a net resummation effect even in total cross sections in the presence of fiducial cuts. I compare our predictions for the Z boson transverse-momentum spectrum to high-precision measurements by the ATLAS and CMS experiments, discussing in turn the estimation of residual perturbative uncertainties, parametric uncertainties from the strong coupling and collinear PDFs, and uncertainties arising from the nonperturbative transverse structure of the proton as encoded in TMD PDFs and their evolution. I conclude by discussing synergies with the TMD program at the future Electron-Ion Collider at BNL and ongoing computational campaigns in lattice QCD.
Wednesday October 26 at 3:30pm in 2C8
Dr Julia Gonski (Columbia)
Searching for Uncovered and Unexpected New Physics Signatures at the Energy Frontier
The 2012 discovery of the Higgs boson with the Large Hadron Collider (LHC) was a groundbreaking achievement for high energy physics. Remaining puzzles such as dark matter confirm the need for beyond the Standard Model physics, and the Higgs boson can be used as a compass to determine its nature. This talk focuses on novel ATLAS searches in under-covered phase space, specifically long-lived particles and heavy resonances, that make use of the Higgs along with advanced data analysis techniques such as machine learning and anomaly detection for broad sensitivity. The High Luminosity LHC, the corresponding ATLAS detector upgrade, and studies for future colliders are all crucial for the longevity of these searches. These topics are discussed in the context of long-term planning for future experiments and the continued success of the field.
Wednesday November 30 at 3:30pm in 4C2
Professor Lam Hui (Columbia)
Black hole perturbation theory: Love numbers and nonlinear ring down.
We will briefly review black hole perturbation theory and discuss two new developments: (1) the symmetry reason behind the well known vanishing of the Love numbers, which characterize a black hole’s static tidal response; (2) the generation and production of first and second order quasi-normal modes in the ring down of a black hole. If time permits, we will also discuss the black hole as a probe of new light degrees of freedom, including wave dark matter such as an axion.
Note also annual review article on wave dark matter https://arxiv.org/abs/2101.11735
Wednesday December 14 at 3:30pm in 2C8
Dr Mark Palmer (BNL)
Future Colliders
Note Dr Mark Palmer is the director of the accelerator test facility at BNL and an expert on future colliders.
Seminars in 2021
Wednesday March 17 2021 at 4pm
Jonathan Asaadi (University of Texas Arlington)
Q-Pix: Pixelated readout of kiloton scale noble element time projection chambers
Future long baseline neutrino experiments such as the Deep Underground Neutrino Experiment (DUNE) call for the deployment of multiple multi-kiloton scale liquid argon time projection chambers (LArTPCs). To date, two detector readout technologies are being studied in large-scale prototype detectors: the single phase (SP) and dual phase (DP) detectors using projective charge readout wire based anode planes. These projective readout technologies come with a set of challenges in the construction of the anode planes, the continuous readout of the system required to accomplish the physics goals of proton decay searches and supernova neutrino sensitivity, and the 2D projective reconstruction of complex neutrino topologies.
The Q-Pix concept (arXiv: 1809.10213) is a continuously integrating low-power charge-sensitive amplifier (CSA) viewed by a Schmitt trigger. When the trigger threshold is met, the comparator initiates a ‘reset’ transition and returns the CSA circuitry to a stable baseline. This is the elementary Charge-Integrate / Reset (CIR) circuit. The instance of reset time is captured in a 32-bit clock value register, buffers the cycle and then begins again. What is exploited in this new architecture is the time difference between one clock capture and the next sequential capture, called the Reset Time Difference (RTD). The RTD measures the time to integrate a predefined integrated quantum of charge (Q). Waveforms are reconstructed without differentiation and an event is characterized by the sequence of RTDs. In quiescent mode the RTDs will be evenly spaced with time intervals of seconds between RTDs with an event signaled by the appearance of a sequence of varying $\mu$s RTDs. This technique easily distinguishes the background RTDs due to 39Ar decays (which also provide an automatic absolute charge calibration) and signal RTD sequences due to ionizing tracks. Q-Pix offers the ability to extract all track information providing very detailed track profiles and also utilizes a dynamically established network for DAQ for exceptional resilience against single point failures. A number of novel ideas could be pursued to allow the Q-Pix design to be an integrated tracking/photo-detector. One such more speculative notion is the exploration of coating the dielectric surface with a type of photo-conductor which would respond to the VUV light incident on the surface. When struck by a VUV photon, the photoconductor would have electrons elevated into the conduction band and move in the electric field toward a pixel button. Initial R&D and simulation work on the Q-Pix concept will be presented in this work.
Wednesday April 14 2021 at **4pm**
Nedaa Alexandra Asbah (Harvard)
Evidence of the four-top-quark production at the LHC
A summary of the latest results on the evidence of the four-top-quark production using proton-proton collision data at a centre of-mass energy of 13 TeV collected by the ATLAS detector at the Large Hadron Collider with an integrated luminosity of 139 fb−1. Events are selected if they contain a same-sign lepton (electron or a muon) pair or at least three leptons (2lSS/3l) or a single lepton or an opposite-sign lepton pair (1l/2lOS). A multivariate technique is used to discriminate between signal and background events in the signal rich regions. The combined four top-quark production cross section is measured to be 24 +7/−6 fb, with a corresponding observed (expected) signal significance of 4.7 (2.6) standard deviations over the background-only predictions. It is consistent within 2.0 standard deviations with the Standard Model expectation of 12.0 ± 2.4 fb.
Seminars in 2020
Tuesday January 14 2020 at 2pm in 2C6
Ben Nachman (LBNL)
Deep Learning, Quantum Information, and the LHC as a Gluon Factory
Jets produced from high-energy quarks and gluons are ubiquitous at the Large Hadron Collider (LHC). These objects can be used to study emergent quantum properties of the strong force as well as search for new particles and forces beyond the Standard Model. As a jet can have O(100) particles, analyzing jets is inherently a high-dimensional problem. Therefore, jet physics has been leading the integration and development of modern machine learning tools for high-energy physics. This high dimensionality also is a challenge for classical techniques to account for all quantum effects in the evolution of jet formation. I will start by discussing the exciting new field of precision jet substructure, with the latest results from the ATLAS experiment and interpreted in the context of new theory calculations. This sets the stage for two exciting parallel developments where quantum computers and machine learning may lead to fundamentally new insights. After briefly mentioning the potential of quantum algorithms, I will illustrate the power of deep learning with a new class of algorithms called weak supervision that can learn directly from (unlabeled) data and potentially uncover high dimensional structures hidden from our ordinary three-dimensional view. In this way, machine learning can help us learn something new and fundamental about nature.
Monday February 10 2020 Joint Theory & Experiment Seminar
Nathaniel Craig (University of California, Santa Barbara)
See recent papers
Wednesday October 28 2020 at 4pm
Tova Holmes (University of Tennessee)
Off the Beaten Track: Long-Lived Particles at the LHC
The LHC has reached a new era: nearly a decade without any large jumps in energy or luminosity. For those interested in finding Beyond the Standard Model (BSM) physics, a paradigm shift is required. In my talk I’ll discuss a search program looking for long-lived particles, which often escape detection from standard BSM searches, due to the difficulty of triggering on and reconstructing their unconventional signatures. These challenges result in a long-lived particle landscape full of unexcluded territory, opening up opportunities to find TeV-scale Supersymmetry, hidden sectors, right-handed neutrinos, and more. My talk will focus on the challenge of triggering in these searches, and how we can expand our capability to explore these new signatures.
Wednesday November 18 2020 at 4pm
Stephanie Majewski (University of Oregon)
Searching for the Supersymmetric Partner to the Top Quark at ATLAS: Don’t Stop Believin’
The discovery of the stop — the Supersymmetric partner of the top quark — is a key goal of the ATLAS physics program enabled by the Large Hadron Collider. I will review the status of the search for direct stop pair production, focusing on stop decays via a hadronically decaying top quark and the lightest Supersymmetric particle (a compelling dark matter candidate). I will also discuss recent developments in the natural “stealth stop” regime, where the stop is nearly degenerate with the top quark, which is characterized by decay kinematics that force the final state top quark off its mass shell. Our recast of the ATLAS top mass measurements revealed that stop decays in this regime could contaminate the measurement of the top mass by up to 2 GeV. Thus, a robust statement on the exclusion of a stealth stop requires the simultaneous consideration of the impact on the top mass.
Wednesday December 2 2020 at 4pm
Louise Skinnari (Northeastern University)
Track-triggering at CMS for the High-Luminosity LHC
The high luminosity upgrade of the Large Hadron Collider (LHC), scheduled for 2025-2027, will significantly increase the instantaneous luminosity of the LHC collisions. The resulting large proton-proton collision datasets will allow precise measurements of Higgs boson properties, searches for very rare processes, and much more. To cope with the challenging experimental environment resulting from the high luminosity, significant upgrades will be required for the LHC detectors. A key upgrade of the CMS detector is to incorporate the identification of charged particle trajectories in the hardware-based trigger system, with potential to not only solidify the CMS trigger strategy but to enable searches for completely new physics signatures. This seminar will discuss the motivation of the CMS track trigger, give an overview of the system, and discuss its expected performance based on simulation and hardware demonstration.
Seminars in 2019
>Wednesday February 6 2019 at 4:00pm in room A8
Elena Guardincerri (LANL)
Muon Radiography at the Los Alamos National Laboratory and Brunelleschi’s dome in Florence
Cosmic-ray muons are free, ubiquitous, very penetrating particles. Muon radiography takes advantage of them to probe objects that, because of their thickness or the shielding around them, would be out of the reach of more traditional radiographic
techniques. I will briefly review the different techniques that are currently used to perform cosmic-ray muon radiography and discuss some applications to actual problems. I will discuss, in particular, the use of cosmic ray muons to assess the content of dry casks containing spent nuclear fuel, an important task to maintain continuity of knowledge over the fuel itself and avoid its diversion. I will then show how muon induced neutron emission can be used to image high Z materials. Lastly I will discuss the use of cosmic ray muons to image the interior of thick walls for historic preservation purposes and our plans to image the interior wall of the cathedral of Florence, Italy
**Tuesday February 19 2019 at 1:30pm in room 4N12**
Shaomin Chen (Tsinghua University)
Jinping Neutrino Experiment
**Tuesday March 12 2019 at 1:30pm in room 4N12**
Boris Kayser (Fermilab)
Addressing the Majorana vs. Dirac Question Using Neutrino Decays
Wednesday March 20 2019 at 4:00pm in room A8
Kate Scholberg (Duke)
Coherent neutrino scattering
Wednesday April 3 2019 at 4:00pm in room A8
Richie Bonventre (LBNL)
Searching for muon to electron conversion: The Mu2e experiment at Fermilab
The Mu2e experiment will measure the charged-lepton flavor violating (CLFV) neutrino-less conversion of a negative muon into an electron in the field of a nucleus. Mu2e will improve the previous measurement by four orders of magnitude, reaching a 90% C.L. sensitivity to CLFV conversion rates of 8×10^-17 or larger. The experiment will reach mass scales of nearly 10^4 TeV, far beyond the direct reach of colliders. It will be sensitive to a wide range of new physics, complementing and extending other CLFV searches. Mu2e is under design and construction at the Muon Campus of Fermilab, and we expect to start taking physics data in 2023. I will present the physics motivation for Mu2e, the detector design, and the current experimental status.
Wednesday May 8 2019 at 10:00am in room A4
Brian Beckford (Michigan)
Latest results from KOTO
Thursday May 9 2019 at 1:30pm in room 2C8
Tomohiro Yamazaki (Tokyo)
Search for the supersymmetric partner of the top quark with the ATLAS detector
Supersymmetry (SUSY) is one of the promising extensions of the
Standard Model that provides a solution to the hierarchy problem.
Natural SUSY favors a scenario where a supersymmetric partner of the
top quark (stop) has a mass light enough to be produced at the LHC,
and the stop subsequently decays into higgsinos, supersymmetric
partner of the Higgs bosons, as the lightest supersymmetric particle
(LSP). In the compressed stop scenario where the stop mass is close to
the LSP mass, the identification and reconstruction of low-pt
b-hadrons are crucial. In this talk, the latest result of the stop (to
higgsino) search is presented together with the recent development of
a new b-tagging technique targeting the low-pt b-hadrons.
Wednesday October 9 2019 at 3pm in A4
Max Swiatlowski (TRIUMF)
Searching With di-Higgs Final States at ATLAS: A Window to the Standard Model and Beyond
The discovery of the Higgs boson has been a triumph for the Large Hadron Collider’s physics program, but many open questions remain
about this mysterious particle. Why is the Higgs mass so many orders of magnitude lower than the straightforward prediction? Can we observe
the shape of the Higgs potential which gives rise to the particle, and can this potential be related to cosmological inflation or
baryogenesis? Final states with two Higgs bosons, though extremely rare, can provide answers to these questions and more. I will present
new ATLAS results for searches for direct di-Higgs production, including full run 2 results in the vector boson fusion production
mode, as well as searches for electroweak supersymmetry involving decays to pairs of Higgs bosons. These searches employ several key
innovations, such as the use of b-jet triggers and Boosted Decision Trees in background estimation, to achieve some of the strongest
sensitivities yet to di-Higgs production and provide new insights into the nature of the Higgs.
Monday October 21 2019 at 3pm in A4 Joint Theory & Experiment Seminar
Patrick Meade (SUNY Stony Brook)
See recent papers
Wednesday October 30 2019 at 3pm in room 4C2
Stefano Zambito (Harvard University)
Hunting for Supersymmetry at the LHC A Dive into Naturalness… And Beyond
After the discovery of the Higgs Boson, the predictions of the Standard Model of particle physics can
be extrapolated without inconsistencies all the way up to the Planck mass. Despite this tremendous
success, we still remain in the dark about many open puzzles. Why is the weak interaction much
stronger than gravity? What is the nature of Dark Matter? Are the strong, weak and electromagnetic
forces a lower-energy manifestation of one single fundamental interaction? A possible solution to these
questions is provided by Supersymmetry. The key assumption behind many natural supersymmetric
models is that the masses of the gluinos, the top squarks and the higgsinos are near the TeV scale, thus
within the LHC reach. In this presentation, I will introduce some of the theoretical and phenomenological
arguments that motivate the quest for Supersymmetry. I will then outline how I searched for
the above-mentioned particles using LHC Run-2 data collected by the ATLAS experiment. Finally, I
will focus on my vision of the future and my research plans in high-energy experimental physics.
Friday November 1 2019 at 2pm in room 3W2
Chunhui Chen (Iowa State University)
Higgs Boson decay as a probe to new physics beyond the standard model
Despite being a remarkably simple theoretical model, the Higgs mechanism is the only known theory that is connected to
some of the most profound mysteries in the modern physics: dark energy, dark matter and missing antimatter.
Measurements of the Higgs boson decay may shed light on those open questions. In this talk, I will present a few
selective results from the ATLAS experiment on the Higgs boson decays. Namely the first observation of the Higgs boson decay
to a pair of b-quarks, which had eluded us for many years despite it being the most probable Higgs decay channel;
novel techniques to search for potential new physics using the hardonically decaying Higgs boson, and a first search for singly
produced long-lived neutral particle that may be realized via Higgs portal. The talk will mainly focus on general descriptions
of the measurements without too much technical details, so that the content is accessible to non experimental collider physicists.
Monday November 4 2019 at 3pm in A4 Joint Theory & Experiment Seminar
Andre de Gouvea (Northwestern University)
See recent papers
Wednesday November 6 2019 at 3pm in 4C2
Yongbin Feng (University of Maryland)
Search for emerging jets and other long-lived states with the CMS experiment
Many proposed extensions of the Standard Model contain particles with long lifetimes. When produced at the Large Hadron Collider (LHC) at CERN, these long-lived particles can produce displaced vertices and other non-conventional signatures. In this talk, I will present some recent results from searches for long-lived particles obtained using data collected by the CMS experiment at Run-II of the LHC. I will focus in particular on a model called “dark QCD” with “emerging jet” signatures.
Wednesday November 20 2019 at 3pm in 4C2
Christopher Palmer (Princeton University)
Observation of the Higgs boson decaying to bottom quarks at CMS
The Higgs boson decay to a bottom quark-antiquark pair has been sought
for decades by the high energy community (i.e. at LEP and Tevatron).
LHC experiments built analyses based on the experience of Tevatron
experiments’ analysis techniques. With the observation of the Higgs
boson at LHC during Run 1, the search for this decay channel became
sharply focused. As the bottom quark pair channel is the most
probable decay of the Higgs boson (58%), its observation is both
important in terms of quantifying the Higgs boson and it represents an
important milestone in high energy physics. The results presented use
datasets from the LHC Run 1 and Run 2 (2016+2017) from CMS. This Run
2, 13 TeV dataset corresponds to an integrated luminosity of ~80
fb^-1. The analysis strategy, the background estimation techniques,
and significant analysis improvements from the 2017 data analysis in
CMS are shown. An outlook on the upcoming analysis of the full Run 2
dataset (and beyond) will be discussed.
Seminars in 2018
Wednesday January 24 2018 at 4:00pm
Mark Vagins, University of Tokyo
Zen and the Art of Gadolinium-Loaded Water Cherenkov Detectors
Water Cherenkov detectors have been used for many years to study neutrino interactions and search for nucleon decays. Super-Kamiokande, at 50 kilotons the largest such underground detector in the world, has itself enjoyed over two decades of interesting and important physics results. Looking to the future, for the last fifteen years extensive R&D on a potential upgrade to the detector known as GADZOOKS! has been underway and is now complete; the project has been formally approved, and the detector will be prepared for Gd loading starting this summer. The benefits and challenges of enriching Super-K with 100,000 kilograms of a water-soluble gadolinium compound – thereby enabling it to detect thermal neutrons and dramatically improving its performance as a detector for supernova neutrinos, reactor neutrinos, atmospheric neutrinos, and also as a target for the T2K long-baseline neutrino experiment – will be discussed.
April 10 2018
Michael Ramsey-Musolf (UMass Amherst)
TeV Scale Lepton Number Violation: Neutrinoless Double Beta Decay & the LHC
Tuesday August 7 2018 at 1:30pm in room 2C4
Lawrence Lee (Harvard University)
Searches for Supersymmetry with ATLAS
Monday August 27 2018 at 1:00pm in room 3W2
Sarah Williams (University of Cambridge)
Exploring the landscape of electroweak supersymmetry at the LHC: a quest for a better understanding of dark matter
Thursday September 27 2018 at 3:00pm in room 3C8
Soo-Bong Kim (Seoul National University)
Anomaly of Dancing Reactor Antineutrinos
The Reactor Experiment for Neutrino Oscillation(RENO) started data-taking from August, 2011 and has observed the disappearance of reactor electron antineutrinos to measure the smallest neutrino mixing angle theta13. The experiment has analyzed roughly 2200 days of data to make an accurate measurement of the oscillation amplitude and frequency based on energy and baseline dependent disappearance of reactor antineutrinos. RENO’s precisely measured flux and spectral shape of reactor antineutrinos has shown a deficit in the flux and an excess in the region of 5 MeV relative to the most commonly used model. Furthermore, it has observed fuel-composition dependent variation of reactor antineutrino yield and spectrum. We find that reevaluation of 235U’s antineutrino yield per fission may mostly solve the reactor antineutrino anomaly. We also report a hint of correlation between the 5-MeV excess and the 235U fuel isotope fraction.
Wednesday October 17 2018 at 4:00pm in room 2C2
Shirley Li (SLAC)
Solar neutrino sensitivity of DUNE
Wednesday October 24 2018 at 4:00pm in room A8
Alysia Marino (University of Colorado Boulder)
Recent results from T2K
Wednesday November 7 2018 at 4:00pm in room A8
Or Hen (MIT)
Short-range correlation studies in nuclei
Monday December 10 2018 at 2:30pm in room 4N12
Danielle Norcini (Yale)
First results from the PROSPECT reactor neutrino experiment
Experiments at nuclear reactors have played a key role in determining the properties of the weakly-interacting neutrinos. Results from recent reactor experiments suggest a disagreement between the observed antineutrino flux and energy spectrum when compared to predictions. Beyond the Standard Model sterile neutrinos and corrections to complex nuclear models have been posed to explain the discrepancy. To address this physics, the PROSPECT experiment precisely measures antineutrino energy spectra at multiple, very short baselines (< 10m) from the High Flux Isotope Reactor. This talk details the first sterile neutrino oscillation search and measurement of the uranium-235 antineutrino spectrum from PROSPECT.
Seminars in 2017
Tuesday September 19 2017 at 1:30pm
Shih-Chieh Hsu, University of Washington
Hunting for Dark Matter with Boosted Higgs Bosons in ATLAS
Although dark matter (DM) contributes a large component of the mass-energy of the universe, its properties and interactions with known particles remain unknown. In light of this unsolved puzzle, searches for DM pair-produced at Large Hadron Collider (LHC) provide important information complementary to direct and indirect searches in order to determine whether a signal observed experimentally indeed stems from DM. In this presentation, I will report the latest search results of DM pair production in association with a Higgs boson using the LHC Run2 data (sqrt(s)=13 TeV) collected by the ATLAS detector. I’ll demonstrate the improvement of the analysis using the state-of-the-art boosted Higgs boson techniques. Because the observed data are found to be consistent with the expected Standard Model backgrounds, I’ll show results interpreted using Z’-2HDM simplified models with the most stringent limits. Finally, I will discuss the prospects of this search in the coming LHC Run2 and new ideas of the boosted Higgs tagging.
Tuesday February 21 2017 at 1:30pm in 2C8
Jorge Chaves, Cornell
Search for right-handed W and heavy neutrinos in the 2l+2j final state at CMS
Despite the discovery of the standard model (SM) Higgs boson, there are still unanswered questions that are not explained by the SM, such as the nature of the chiral structure of weak interactions. During Run-1 at the LHC, no clear signs for physics beyond the SM were seen, but there were a few hints of possible new physics. One particular hint was a 2.8\sigma excess seen at the CMS experiment in the search for a heavy right-handed W and heavy neutrino. These particles arise when a left-right symmetry is added to the electroweak sector. In this seminar, I will discuss the Run-1 excess and show preliminary results from the current search with CMS at 13 TeV for a right-handed W in the two leptons plus two jets final state. Additionally, I will discuss the high-luminosity upgrade of the CMS tracker focusing on a proposed track-trigger system to be realized using FPGA technology.
Seminars in 2016
Tuesday December 20 2016 at 1:30pm in 4C8
Shion Chen, University of Tokyo
Quest for gauginos in LHC-Run2 / ATLAS
Despite no significant beyond-the-standard model signatures has been observed in LHC Run1, the discovery of standard model higgs brought a substantial impact on supersymmetry search. As typical minimal models naively need O(10TeV) light flavor sfermions to reconcile with the 125 GeV higgs, there is a grown motivation in searching gauginos which are almost free from the higgs mass constraint. Gluino is in particular an interesting target in early Run2 as the production cross-section greatly enhanced by the doubled center-of-mass energy, and the status is quickly evolving along luminosity. Searching EWKinos, especially for realistic scenarios where the mass spectra is compressed, has more challenges due to their low production cross-section, poor S/N and trigger issue etc., however these are starting to be overcome by recent effort and emerging large data statistics of Run2 and later. This talk will cover the status-quo and prospect of both searches in the ATLAS experiment, with particular focus on (1) up-to-date analysis of gluino search in 1-lepton final state, and (2) R&D studies on multi-variate techniques for the compressed spectra analysis of EWKino search.
Tuesday December 13 2016 at 1:30pm in 4C8
Alessandro Tricoli, Brookhaven National Laboratory
A new era of precision physics with di-bosons at the LHC
The Run-2 of the LHC has opened up a new window on precision physics measurements. Thanks to higher cross sections of physics processes at 13 TeV compared to 7 and 8 TeV centre-of-mass energies, the increasing amount of data being collected and sophisticated experimental techniques, we can reach high precisions on measurements of properties of rare processes such as the production cross sections of two massive electroweak gauge bosons, for example two W bosons. LHC results on di-boson production cross sections at different centre-of-mass energies constitute stringent tests of both the strong and the electroweak sectors of the Standard Model and provide a model-independent mean to search for new physics at high energy scales. The high experimental precision recently achieved in several Run-1 measurements at the LHC together with hints of discrepancies observed between some di-boson measurements and Standard Model predictions have prompted significant progress in calculations at high orders in perturbation theory. This global effort has led in the past months to the so-called “next-to-next-to-leading order revolution”, i.e. and explosion of new calculations that can reach percent level precision in the calculation of several processes including di-boson production cross sections. We are indeed on the threshold of a new era of precision physics for di-boson production at the multi-TeV energy scales. This seminar will focus on recent measurements of inclusive and differential cross sections for WW production at centre of mass energies of 13 TeV and 8 TeV by the ATLAS Collaboration at the LHC.
Tuesday December 6 2016 at 1:30pm in 4C8
Allison McCarn, University of Michigan
Searches for New Physics Through Third Generation Particles at the ATLAS Detector
The Standard Model (SM) has been central to particle physics for decades, and its success in predicting observational results has
culminated in the 2012 discovery of a Higgs boson at the Large Hadron Collider. However, the theory is considered ‘not natural’, requiring
finely-tuned parameters to allow for the precise cancellation of large radiative corrections to the Higgs boson mass. In pursuit of a more
natural theory, extensions to the SM have been proposed that would stabilize the Higgs boson mass and resolve the hierarchy problem
(supersymmetry, extended Higgs sectors, models with vector-like quarks). This presentation will focus on several ATLAS searches for
new physics involving third generation particles, both targeting extended Higgs sectors and vector-like quarks.
Tuesday November 15 2016 at 1:30pm in 4C8
Matthew Klein, Columbia University
Search for supersymmetry in events with four or more leptons at ATLAS
Tuesday November 1 2016 at 1:30pm in 4C8
John Alison, University of Chicago
Di-Higgs at the LHC: Current Status and Future Prospects
I will discuss motivations for searching for di-Higgs production at the LHC. Recent results and projected sensitivities will be
presented with particular emphasis on the dominant hh->4b channel.
Thursday October 27 2016 at 3pm in room DRL A6
Andrew Missert, University of Colorado, Boulder
Improving T2K Oscillation Results with a Maximum Likelihood Event Reconstruction
The Tokai-to-Kamioka (T2K) experiment is an accelerator-based long-baseline neutrino oscillation experiment that uses a unique off-axis neutrino beam to precisely measure the parameters that govern neutrino flavor oscillations. This talk will outline the experiment and the current results, which offer tantalizing hints regarding the existence of CP violation in the neutrino sector. It will also cover future improvements to the T2K analysis, most notably the development of a new maximum-likelihood event reconstruction algorithm for Super Kamiokande, which could be used to squeeze even more information about the oscillation parameters from the existing data.
Friday October 14 2016 at 1:30 pm in room 4C6
Adi Bornheim, Caltech
Precision Timing Detectors for Particle Physics
High energy particle collider experiments are facing ever more challenging conditions, operating at todays accelerators which are providing instantaneous luminosity of 1034 cm-2s-1 and above. The high center of mass energy, the large number of simultaneous collisions of beam particles and the very high repetition rates of the collision events pose huge challenges. This results in extremely high particle fluxes, causing very high occupancy in the detectors operating at these machines. Detectors which can provide timing measurements with a precision of a few 10 ps and below can be a major aid in the reconstruction of the physics events under such challenging conditions. In this talk I will present a broad range of R&D activities on precision timing detectors with a focus on calorimeter based measurements. I will discuss possible implementations of precision timing detectors for the upgrades of the LHC detectors to cope with the conditions expected at the high luminosity upgrade of the accelerator as well as for future colliders.
Colloquium: Primakoff lecture, October 13
Rolf Heuer, CERN (former director general)
Tuesday September 20 2016 at 3pm in room 2C8
Jonathan Insler, Drexel University
Results from the DUNE 35-ton Prototype Detector
The 35 ton prototype for the Deep Underground Neutrino Experiment (DUNE) far detector was a single phase liquid argon time projection chamber (LAr-TPC) integrated detector that took cosmics data for a six week run from February to the middle of March 2016. The 35 ton was built to test the liquid argon technologies to be used by the full size DUNE far detector in a fully integrated system. The 35 ton had two drift volumes of lengths 2.23 m and 0.23 m on either side of its anode plane assembly (APA) and made use of wire planes with wrapped wires and a photon detection system (PDS) utilizing photon detection panels read out by silicon photomultipliers (SiPMs). We present an analysis of 35 ton detector cosmics data with a focus on the performance of the PDS.
Tuesday May 24 1:30pm in 3c4
Alexis Popkow, UCLA
Galactic Very High Energy Astrophysics
Despite being discovered over a hundred years ago, the origin of cosmic rays has remained a mystery. Recent clues suggest that a large number are accelerated in supernova remnants in our Galaxy. The Cygnus region is a very active region of our Galaxy, with many sources of GeV and TeV gamma-ray emission, such as supernova remnants, pulsar wind nebulae, and massive star clusters. A detailed study of the Cygnus region can give insight into the processes of particle acceleration in astrophysical sources, and the nature of cosmic rays. VERITAS (Very Energetic Radiation Imaging Telescope Array System) is an array of four 12 meter diameter imaging atmospheric Cherenkov telescopes located at Mt Hopkins, AZ, USA. From 2007 through 2012 it gathered nearly 300 hours of data in the Cygnus region from 67 to 82 degrees Galactic longitude and from -1 to 4 degrees in Galactic latitude. We are reanalyzing the VERITAS data with updated analysis techniques, and will be cross correlating that data with the results of an analysis of over five years of Fermi-LAT data in the region. Using a cross correlation of these results we can motivate continued observations in this active region of the Galaxy.
Monday May 16 3:30pm in **3N6**
Jordan Myslik, University of Victoria
Muon antineutrino oscillations at T2K
The T2K (“Tokai to Kamioka”) experiment is a long-baseline neutrino oscillation experiment in Japan. A beam of muon neutrinos or muon
antineutrinos is produced at the Japan Proton Accelerator Research Complex (J-PARC) in Tokai. The unoscillated neutrino flux is measured
by the near detector complex 280 m from the proton target, and the oscillated neutrino flux is measured by the far detector,
Super-Kamiokande, 295 km away. Using a beam of muon neutrinos, T2K has performed precise measurements of muon neutrino disappearance, and
discovered muon neutrino to electron neutrino oscillation by measuring electron neutrino appearance. Since the summer of 2014, T2K has been
taking data using a beam of muon antineutrinos, and has released the results of both a muon antineutrino disappearance analysis and an
electron antineutrino appearance analysis, both using antineutrino beam data up to the summer of 2015. This talk will discuss these analyses,
going into detail about the role played by the near detector, and looking at future directions.
Wednesday May 4 1:00pm note time in 4N12 note place
David Nygren, University of Texas Arlington
Searches for Neutrino-less Double Beta-Decay: a Decade of Discovery Ahead at the ton-scale?
Observation of neutrino-less double beta-decay would demonstrate that the neutrino and anti-neutrino are identical. This decay mode would be
prohibited if the neutrino has zero mass but the discovery of neutrino oscillations, demonstrating a non-zero mass, has strongly motivated new experimental searches. While knowledge of mass and phases is incomplete, oscillation results have provided a target range of desired search sensitivity, about a factor of about 100 greater than the current experimental limits. I will present a personal perspective on current experimental aspirations in the international context. A ‘discovery class’ experiment requires a ton-scale active mass and background levels reduced by more than two orders of magnitude. Is this technically possible? For the US, an opportunity appears to exist in the use of
gas-phase xenon with development of new methods for background reduction, as pursued within the NEXT collaboration. The elusive
neutrino may yet provide more surprises, even insight as to why there is something, rather than nothing.
Thursday April 28 11:00am in 3W2
Keisuke Yoshihara, Penn
Recent results on SUSY searches in LHC-ATLAS
Despite the absence of experimental evidence, weak scale supersymmetry (SUSY) remains one of the best motivated and studied SM extensions as a solution for hierarchy problem. This talk summarizes the recent ATLAS results on SUSY searches using ~3/fb of 13TeV proton-proton collisions in 2015 and discusses what to do next in the coming years.
Tuesday April 5 1:30pm in 3W2
Chris Hays, Oxford University
Effective field theory and the LHC: New physics through precision measurement
Tuesday March 29 1:30pm in 3W2
Jeff Dandoy, University of Chicago
Search for new phenomena in the dijet channel with the ATLAS detector at 13 TeV
With the beginning of Run II at the LHC, proton-proton collisions at a center of mass energy of 13 TeV have introduced new potential for observing physics beyond the Standard Model. The increase in center of mass energy greatly enhances the reach of searches for any new exotic particles, particularly with decay modes involving a dijet system. With 3.6 fb^{-1} collected so far in Run II, the sensitivity to new resonant particles has already surpassed the limits set with the full Run I dataset. The ability to observe non-resonant deviations from the SM such as structure within quarks themselves has also been greatly enhanced from the new operating conditions of the LHC. I will present the first results of searches for both resonant and non-resonant new physics in dijet events.
Tuesday March 22 1:30pm in 3W2
Joe Taenzer, University of Toronto
Studying V(H → WW*) with the ATLAS detector and Global sequential corrections for ATLAS jets
Tuesday March 15 1:30pm in 3W2
Philip Chang, University of Illinois
Searches for new physics in the Higgs sector
The discovery of the Higgs boson opened up a new frontier for new physics searches. One example is the study of the Higgs couplings. Precise measurement of the Higgs couplings can put constraints on new physics. I will discuss the couplings measurement in H->WW decay channel that provides the best single channel measurement. I will also then briefly discuss other ways of searching for new physics in the Higgs sector for the future.
Tuesday March 1 2016 in 3W2 at 1:30pm
Sadia Khalil, Kansas State University
Searches for Vector-like quarks at CMS experiment, at the LHC.
I will present results of searches for massive top and bottom quark partners using proton-proton collision data collected with
the CMS detector at the CERN LHC at a center-of-mass energy of 8 TeV. These fourth-generation vector-like quarks are postulated
to solve the Hierarchy problem and stabilize the Higgs mass, while escaping constraints on the Higgs cross section measurement.
The vector-like quark decays result in a variety of final states, containing top and bottom quarks, gauge and Higgs bosons.
I will present searches using several categories of reconstructed objects, from multi-leptonic to fully hadronic final states.
At 8 TeV, we set exclusion limits on both the vector-like quark mass and pair-production cross sections, for combinations of the
vector-like quark branching ratios. I will also present these searches using 13 TeV collision data.
Tuesday February 23 2016 in 3W2 at 1:30pm
David Shih, Rutgers University
Natural Supersymmetry Today
I’ll give a broad overview and survey of my work and others on the challenges confronting naturalness and supersymmetry after Run I of the LHC.
Colloquium: Wednesday February 17 4:15pm in A8
Lian Tao Wang, University of Chicago
Physics opportunities at future circular colliders
Tuesday February 9 2016 in 3W2 at 1:30pm
Russell Neilson, Drexel University
PICO: Searching for Dark Matter with Bubble Chambers
The PICO collaboration uses bubble chambers to search for WIMP dark matter particles. The bubble chambers are operated in a moderately superheated state providing superb rejection of the dominant gamma background at better than the 10^-10 level, and are filled with fluorinated target fluids ideally suited for investigating spin-dependent WIMP-proton interactions. PICO is currently running two experiments at the deep underground SNOLAB site: PICO-60 (previously called COUPP-60) and PICO-2L. I will present results from recent dark matter searches in both of those experiments. I will also discuss studies of unexpected backgrounds that have impacted those dark matter searches and future plans for the two experiments.
Seminars in 2015
Tuesday December 1 2015 in 3W2 at 1:30pm
Yangyang Cheng, University of Chicago
Tracking to the Dark Side at ATLAS: the Present and the Potential
Tuesday November 17 2015 in 3W2 at 1:30pm
Michelle Dolinski, Drexel University
Searching for neutrinoless double beta decay with cryogenic xenon detectors
Thursday November 12 2015 in 3W2 at 1:30pm
Sinead Farrington, Warwick University
Results on the Standard-Model-like Higgs boson at LHC Run 1
Tuesday September 22 2015 in 3W2 at 1:30pm
Nick Ryder, University of Oxford
The SoLid Experiment: searching for neutrino oscillations within 10 m of a nuclear reactor
Tuesday June 2 2015 in 3W2 at 1:30pm
Kristin Lohwasser, DESY-Zeuthen
The WW puzzle: Measurement of diboson production at the LHC
The measurements of the production of W boson pairs in pp collisions at 7 and 8 TeV have shown a small but consistent excess of 1-2- sigma over the theoretical predictions, causing a bit of a stir amongst theorists and experimentalists alike. The recent results from the updated ATLAS measurements for the total and fiducial cross sections are presented together with a study of differential distributions as well as limits on anomalous triple gauge couplings.
Thursday April 30 2015 in 2C4 at 1:30pm
Mike Hance, LBNL
Searching for Exotic Heavy Leptons and Diboson Resonances at the LHC
Tuesday April 28 2015 in 3W2 at 1:30pm
John Paul Chou, Rutgers
Recent CMS Searches from Run 1 and Prospects for Run 2
Thursday April 23 2015 in 2C4 at 1:30pm
Andrew Brinkerhoff, Notre Dame
A new measurement of ttW and ttZ at CMS
For the first time at the LHC, we are able to measure the associated production of W or Z bosons with top quark pairs. These processes allow us to directly measure the top-Z coupling, and place limits on effective couplings between the top quark and the Higgs, W, and Z bosons. In addition, ttW and ttZ are important backgrounds in searches for ttH and new physics processes in the top sector, especially SUSY models. I will present recent results from ATLAS and CMS, and describe a new technique to reconstruct the ttW and ttZ systems, allowing for more precise measurements with existing data.
Tuesday April 21 2015 in 3W2 at 1:30pm
Justin Khoury, Penn
Dark matter superfluidity
Thursday April 16 2015 in 2C4 at 1:30pm
Ben Carlson, University of Pittsburgh
Search for stealth supersymmetry at the LHC
Supersymmetry (SUSY) can simultaneously solve the hierarchy problem, allow unification of the fundamental interactions, and provide a candidate for dark matter. Most searches for SUSY focus on the presence of large missing transverse energy (MET) carried away by the lightest SUSY particle. Recent high-MET searches at the CERN LHC have not yet found evidence for SUSY. Therefore, it is important to study well-motivated alternatives with low-MET, such as models characterized by R-parity violation, compressed spectra, and hidden valleys. In particular, the “stealth SUSY” model yields a low-MET signature while conserving R-parity by means of a new hidden sector in which SUSY is approximately conserved. I will present recent LHC searches for stealth SUSY, and discuss interesting areas for study at 13 TeV.
Tuesday April 14 2015 in 3W2 at 1:30pm
Brian Hamilton, University of Maryland
New results from LHCb
I will present several new results based on the full dataset collected by the LHCb detector during the 2011 and 2012 running periods. In particular, the first measurement from LHCb of the magnitude of the CKM matrix element Vub via semileptonic decays of the $\Lambda_{b}$ baryon and its impact on contributions of right handed currents will be discussed. I will also present new results on the electroweak penguin decay $B \to K^{*} \mu\mu$ and the status of anomalies in this channel observed in the previous analysis which used a subset of the full data. Plans for the LHCb experiment during Run 2 of the LHC and beyond will also be discussed.
Thursday April 2 2015 in 2C4 at 1:30pm
Alex Tuna, University of Pennsylvania
Higgs boson decay to tau+ tau-
Tuesday March 31 2015 in 3W2 at 1:30pm
Ben Hooberman, University of Illinois
Recent results from LHC dilepton+jets+missing transverse momentum Searches
The discovery of a Higgs boson at the LHC has answered critical open questions in the standard model. Despite strong evidence that the standard model is incomplete, no compelling evidence for beyond-the-standard model physics has been observed. However, two recent searches from CMS and ATLAS in the dilepton + jets + ETmiss final state have uncovered moderate excesses with respect to standard model predictions, at the level of ~2.5-3.0sigma. This talk will discuss the strategy, background estimation, and results of these searches, as well as possible signal interpretations in supersymmetric models.
Thursday March 26 2015 in 2C4 at 1:30pm
John Alison, University of Chicago
Fast Track Finding at the LHC
Tuesday March 24 2015 in 3W2 at 1:30pm
Chase Shimmin, University of California at Irvine
Observing Ultra-High Energy Cosmic Rays with Smartphones
In this talk I discuss the possibility of using a network smartphones and similar devices to search for ultra-high energy ($>10^{18}$ eV) cosmic rays via a community-sourced scientific platform. Muons and energetic photons produced in UHECR events leave a signature of bright pixels in images from on-board CMOS cameras, while GPS location data allows for the reconstruction of extensive air showers observed by multiple devices. The ubiquity of these consumer devices around the globe enables instrumenting a far greater area than conventional observatories, enhancing sensitivity to the very rarest events. Given certain levels of participation, it is even possible to match the observational power of state-of-the-art facilities such as the Pierre Auger observatory, at the highest energies.
Tuesday March 17 2015 in 3W2 at 1:30pm
John Campbell, Fermi National Accelerator Lab
Monte Carlo for FeMtobarn processes (MCFM) and related topics
Wednesday March 4 2015 at 2:00pm in 2C4 at 2:00pm
Alberto Belloni, University of Maryland
Looking towards 2025 – Preparing the CMS hadronic calorimeter for the High-Luminosity LHC runs
Tuesday Feb 24 2015 at 1:30pm in Room 3W2
Holger Muller, University of California, Berkeley
Atom interferometry measurements in fundamental physics
Chameleons are flexible models for dark energy that avoid conflict with laboratory experiments by becoming short-ranged in the presence of dense objects. Probing the chameleon field with atoms rather than bulk matter strongly reduces this “screening.” We developed an atom interferometer inside an optical cavity [1] to reach high reproducibility in tight spaces. Our experiment is the first to rule out a range of chameleon and other dark energy candidates that would reproduce the observed cosmic acceleration [2].
We will also comment on our measurement of the fine structure constant, for which we have boosted atom interferometry into the 10^-10 range by suppressing the effects of so-called diffraction phases [3]. After six data taking campaigns we are close to reporting a new measurement with an anticipated accuracy of about 0.25 parts per billion. This would be similar to the one of the electron’s gyromagnetic anomaly g-2, allowing for new precise tests of quantum electrodynamics. [1] arxiv:1409.7130. Phys. Rev. Lett., in press. [2] arXiv:1502.03888. [3] arXiv:1410.8486.
Seminars in 2014
Keep cleaning up page after here
January 14
Nuno de Barros, Technical University, Dresden
First results on neutrinoless double beta decay from the GERDA experiment
The GERmanium Detector Array (GERDA) is an experiment designed to
search for neutrinoless double beta decay in 76-Ge, with bare
germanium detectors being operated in a cryostat with 65 cubic meters of
liquid argon. This lepton number violating process is predicted by
models beyond the Standard Model of particle physics and its
successful observation would imply that neutrinos are Majorana
particles. Provided that the exchange of light Majorana neutrinos is
the leading mechanism of neutrino-less double beta decay, measuring or
constraining the half-life sheds also light on the absolute neutrino
mass scale.
The experiment started its first phase of operation in November 2011
and ended in May 2013, when an exposure of 21.6 kg.yr was
achieved. Taking under consideration the background index, this
exposure allows to test the existing claim of neutrinoless double beta
decay observation by a subset of the Heidelberg-Moscow collaboration.
In this talk the GERDA experiment will be introduced and the results
of the first phase of the experiment will be presented. Furthermore,
the status of the preparations for the second phase of the experiment
will also be shown, which will have twice as much active mass and a
goal background index of 1 x 10^-3 cts / (keV kg yr), one order of
magnitude lower than the goal of phase I.
January 21
Tae Min Hong, Penn
Practice talk for Fermilab Wine & Cheese
January 28
Chris Meyer, University of Chicago
Dijet production at ATLAS and an improved method for theory comparison
Following the successful completion of Run-I at the LHC, a large number of precision Standard Model measurements are being published. I will focus on the recent dijet production paper, which uses the full 2011 data sample (4.5/fb). In particular, this result uses an improved statistical method for quantitatively comparing theoretical predictions with the data. This method will be a strong tool for determining which PDF sets best describe data in future analyses. Finally, a model of contact interactions is used to show that the published cross sections and their uncertainties can be used by the general community to constrain new models of physics.
February 18
Michael Mooney
Search for the SM Higgs Boson Produced in Association with a Vector Boson and Decaying to Bottom Quarks at the CMS Detector
A search for the Higgs boson produced in association with a W or Z boson and decaying to bottom quarks is presented. A sample of approximately 24/fb of data recorded by the CMS experiment at the Large Hadron Collider, operating at center-of-mass energies of 7 TeV and 8 TeV in 2011 and 2012, respectively, is used to search for events consistent with the signature of two b-jets recoiling with high momentum from a W(lnu), Z(ll), or Z(nunu) decay, where l = electron or muon (or hadronically-decaying tau particle in the case of W bosons). Observed signal significance and 95% confidence level upper limits on the production cross-section relative to the Standard Model prediction are presented for the 110-150 GeV Higgs mass range.
September 16 2014
Joana Miguens, LIP,Portugal
Higgs boson measurements in the H->WW*->lvlv channel with ATLAS (slides)
After the discovery at the LHC, precision measurements of the Higgs
boson are essential to determine its nature. The H->WW*->lvlv decay
channel offers a sensitive experimental signature. The Higgs resonance
mass cannot be reconstructed because of the two neutrinos in the final
state. Nonetheless, once the backgrounds are under control, the large
H->WW* branching fraction and good signal-to-background ratio provide
powerful measurements of the Higgs production and couplings. I will
present the analysis and discuss the results from ATLAS on the
H->WW*->lvlv channel, based on the full dataset collected during Run-I
of the LHC, where an excess of events is observed, providing evidence
for the Higgs boson at mH=125GeV.
September 30 2014
Chunhui Chen, Iowa State University
Production of high transverse momentum vector bosons reconstructed as
single jets and its application to search for NP at the LHC
(slides)
Highly boosted hadronically decaying particles have been widely used as a
unique signature to search for NP at the LHC. In this talk, we present a
measurement of the cross-section for high transverse momentum W and Z bosons
produced in *pp* collisions and decaying to all-hadronic final states by
ATLAS experiment. The measurement is performed by reconstructing boosted W
or Z bosons in single jets. The reconstructed jet mass is used to identify
the W and Z bosons, and a jet substructure method based on energy cluster
information in the jet center-of-mass frame is used to suppress the large
multi-jet background. In this talk, we will also discuss potential
applications of the jet substructure in the jet rest frame in searches for
NP at the LHC.
October 28 2014
Naoko Kurahashi Neilson, Drexel
Detecting Cosmic Neutrinos with IceCube at the Earth’s South Pole
The IceCube Neutrino Observatory has recently discovered
a diffuse flux of astrophysical neutrinos, neutrinos from beyond the
solar system. But how does one collect neutrinos at the South Pole?
Why study neutrinos for astronomy? In this talk, I will try to answer
such questions and show nice pictures from Antarctica. I will also
discuss the multiple diffuse flux analyses in IceCube that observe the
astrophysical flux, and what each can tell us. Spatial analyses that
aim to identify the sources of such astrophysical neutrinos will also
be discussed, followed by an attempt to reconcile all results, to draw
a coherent picture that is the state of neutrino astronomy.
Seminars in 2013
November 12
Keisuke Yoshihara, University of Tokyo
Evidence for the Higgs Boson in the H to WW* to llnunu Channel from the ATLAS Experiment at the LHC
Evidence for the Higgs boson in the H to WW* to ll nunu
Channel is presented using the complete 2011 and 2012 data samples
collected with the ATLAS detector at the LHC. The analysis focuses on
a mass of mH = 125 GeV, where an excess over the expected number of
background events is observed. A preliminary result of coupling and
rate measurement is presented along with some details on the object
selection and background estimation.
November 19
Karen Gibson, Case Western
First Dark Matter Search Results from the LUX Detector
I will present the results from 85 days of data collected by the LUX experiment. The LUX detector is a two-phase xenon time-projection chamber designed to search for the scattering of WIMP dark matter in liquid xenon.
LUX has been operating underground at the 4850′ level of the Sanford Underground Research Facility in Lead, SD, since February 2013, and WIMP search data was collected between April and August 2013. I will review the unblinded analysis of our initial dataset and discuss the results from our search, which provides world-leading sensitivity to WIMP dark matter.
November 26
Sogee Spinner, University of Pennsylvania
Linking Neutrino and Collider Physics through a Theory of R-parity Violation
Proton decay bounds have forced the ad hoc R-parity discrete symmetry to be an integral part of the minimal supersymmetric standard model thereby associating supersymmetry with missing energy signals at the Large Hadron Collider. I will discuss an alternative picture, the minimal version of which to leads to spontaneous R-parity violation with a stable proton. It is further well motivated by string theory. Neutrino masses are generated through R-parity violation therefore intimately connecting the neutrino sector to the decay of the lightest supersymmetric particle (LSP), which is no longer stable. This will be discussed within the context of a stop LSP. Other interesting predictions of the model will be highlighted.
December 3
Nathaniel Craig, Rutgers University
New Searches involving the Higgs boson.
The discovery of a Higgs-like particle at the LHC provides an unprecedented opportunity for the pursuit of physics beyond the Standard Model. In this talk I’ll propose various strategies to look for new physics via the Higgs — including measurements of Higgs couplings and associated indirect observables; searches for Higgs production in association with new physics; and prospects for probing extended electroweak symmetry breaking sectors.
December 10
Patrick Meade, Stony Brook University
Finding new physics in unexpected places
I’ll describe examples of well motivated BSM physics that may be in
current LHC data which is not excluded by direct searches. I’ll
discuss the implications of this for data driven background methods,
and possible new search strategies for the second run of the LHC
Seminars in 2012
Tuesday January 17 at 1:30pm
Erica Caden
Drexel University
Results from Double Chooz
Tuesday April 17 at 1:30pm
Geralyn Zeller
FermilabUnanswered questions in neutrino scattering
Seminars in 2011
Tuesday January 18 at 1:30pm
Rick Van Berg
PENN
LSST (pdf slides)
Tuesday January 25 at 1:30pm
Corrinne Mills
Harvard
W physics results at ATLAS (pdf slides)
The 2010 LHC data from proton-proton collisons at sqrt(s) = 7 TeV give us our first look at matter and forces at an energy scale unprecedented at colliders.
W bosons decaying to a charged lepton and a neutrino are a benchmark Standard Model process, and has the highest cross section of any process producing isolated high-momentum leptons. Although the integrated luminosity of this first data is orders of magnitude below what is projected for the next few years of LHC running, there is already a sufficient number of W candidates to begin characterizing W production at the LHC. I will show measurements by the ATLAS collaboration of the inclusive W cross section and lepton charge asymmetry, and describe a measurement in progress of the transverse momentum distribution of the W. These and similar measurements test our understanding of a new detector and of physics at a new energy scale, establishing the foundation needed to search for evidence of new particles and phenomena.
Tuesday February 1 at 1:30pm
Amit Lath
Rutgers
Search for a new hadronic resonance using jet ensembles at CDF (pdf slides)
Tuesday February 15 at 1:30pm
Mariangela Lisanti
Princeton
Model-Independent Searches at the LHC
EVO Video Recording
Tuesday February 22 at 1:30pm
Doug Glenzinski
Fermilab
The Mu2e experiment
EVO Video Recording
Tuesday March 1 at 1:30pm
Stan Seibert
University of Pennsylvania
MiniCLEANEVO Video Recording
Tuesday March 15 at 1:30pm
Daniel Whiteson
University of California, IrvineExploring the unknown universe with the LHCEVO Video Recording
Collisions at the Large Hadron Collider (LHC) let us explore a new territory nearly four times larger than anything previously examined. This energy frontier may be populated with new particles which (1) shed light on the nature of dark matter (2) extend the current table of the fundamental particles (3) demonstrate the existence of new fundamental forces or (4) reveal startling and completely unexpected properties. I will describe a strategy for searching this territory, show the state of the art from the Fermilab Tevatron collider and present first results from the ATLAS detector at the LHC.
- Tuesday March 22 at 1:30pm
Richard Hughes
Ohio State University - Recent CDF results on the Standard Model Higgs Search
- EVO Video Recording
- Tuesday March 29 at 1:30pm
Roy Briere
Carnegie Mellon University - Early results and prospects at BESIII
- EVO Video Recording
- Tuesday April 5 at 1:30pm
Sarah Demers
Yale University - Recent results from ATLAS on W -> tau nu
- EVO Video Recording
- Tuesday April 12 at 1:30pm
Kathy Copic
Columbia University - Recent results from ATLAS on W’ and Z’ searches
- EVO Video Recording
- Tuesday April 19 at 1:30pm
Richard Gray
Rutgers University - Recent results from CMS on multilepton searches
- EVO Video Recording
- Thursday April 21 at !Note time! 3:00pm
Peter Wittich
Cornell University - Recent results from CMS on W’ searches
- EVO Video Recording
Tuesday April 26 at 1:30pm
Brian Winer
Ohio State UniversityRecent results from FERMIEVO Video Recording
Wednesday October 19 at 1:30pm in 3W2
Dima Kovalskyi
UCSBRecent search results for H->WW with CMS
Tuesday November 1 at 1:30pm
Jeff Temple
University of Maryland
Recent search results for stopped gluinos with CMS
Tuesday November 8 at 1:30pm
Alex Wright
Princeton UniversityRecent results from Borexino
Seminars in 2010
Tuesday January 19 at 1:30pm
Sean Grullon
University of Wisconsin
Searching for High Energy Diffuse Astrophysical Muon Neutrinos with IceCube (slides pdf)
The IceCube Neutrino Observatory is a 1 km^3 detector currently
under construction at the South Pole. Searching for high energy
neutrinos from unresolved astrophysical sources is one of the main
analysis strategies used in the search for astrophysical neutrinos with
the IceCube Neutrino Observatory. A hard energy spectrum of
neutrinos from isotropically distributed astrophysical sources could
contribute to form a detectable signal above the atmospheric
neutrino background. A reliable method of estimating the energy of
the neutrino-induced lepton is crucial for identifying astrophysical
neutrinos. An analysis is underway using data from the 40
string configuration taken during its 2008-2009 science run.
Tuesday February 9 at 1:30pm
Hugh Lippincott
Yale University
DEAP/CLEAN: Detecting dark matter with liquid argon (and neon)
The DEAP/CLEAN collaboration has proposed to use liquid argon and neon
as targets for dark matter and solar neutrinos. I will discuss
measurements of scintillation of these liquids performed at Yale, in
particular focusing on the use of pulse shape discrimination to reject
electronic recoil backgrounds in liquid argon. I will also discuss
studies of alpha and nuclear recoil backgrounds in a prototype detector
currently operating at the underground facility at SNOLAB. If time
permits, I will mention simulations of a large neon detector and their
implications for detecting /pp/ solar neutrinos.
Wednesday March 3 at 2:00pm
Aubra Anthony
University of Colorado
Joint Seminar with Astrophysics-Cosmology
Studying the Sun with SNO: Searching for high-frequency variations in the solar neutrino flux (slides pdf)
Recent helioseismology results have pointed to the possible detection of
high-frequency (periods of minutes to days) gravity-mode oscillation signals
in the Sun. Periodic fluctuations in density, pressure and temperature (as
would be caused by g-modes at the solar core) could potentially modulate the
outgoing flux of solar neutrinos, through the close relationship between
temperature and neutrino production. Density fluctuations could also affect
the propagation of neutrinos through the sun, through the MSW effect,
because periodically-shifting matter densities could temporally vary the
probability for neutrino oscillations to occur. The Sudbury Neutrino
Observatory was an optimal laboratory for studying time dependence in the
solar neutrino flux, due to excellent background elimination and real-time
signal detection. I will discuss the searches that we performed with SNO
neutrino data to identify any high-frequency periodic signal in the sun,
both on broad time scales, as well as those specifically relevant to recent
g-mode detection claims.
Tuesday March 23 at 12:00pm in 2C6
Frank Tackmann
MIT
Event shapes for jet measurements at the LHC
I discuss a new class of event shapes for hadron colliders
which are inclusive observables whose purpose is to enforce
a certain number of (central) jets in the final state.
The simplest case is beam thrust in Drell-Yan, pp -> X l+l-.
Requiring tau_B << 1 provides an inclusive veto for central jets while
allowing forward radiation.
Beam thrust is one of the simplest hadronic observables measurable
at a hadron collider and can provide crucial tests of our
understanding of initial state radiation.
I comment on the theoretical calculation of the cross section
at small tau_B and present explicit results at NNLL, which represents
the first NNLL resummation for a hadron collider event shape.
I also discuss the generalization of beam thrust to processes with
one or more jets. For a certain desired number of jets, the generalized
event shape allows one to constrain additional radiation in
the event and veto undesired jets.
Wednesday April 7 at 4:00pm
Sheldon Stone
Syracuse University
The LHCb Experiment (slides pdf)
I will discuss the physics objectives, design,
commissioning, and first data from the LHCb experiment. I will
also present our plans for an Upgrade.
Monday May 10 at 1:00pm
Ilija Bizjak
University College London
The W-Mass measurement at CDF (slides pdf)
Tuesday October 26 at 1:30pm
Paul Langacker
IAS Princeton
Z’ physics (slides pdf)
Tuesday November 16 at 1:30pm
Burt Ovrut
Penn
B-L MSSM (slides pdf)
Tuesday December 7 at 1:30pm
Sogee Spinner
Wisconsin
The Fate of R-parity(slides pdf)
One of the outstanding problems of supersymmetry is an understanding
of the baryon and lepton number violating terms allowed in the minimal
supersymmetric standard model (so-called R-Parity violating terms).
Explanations which are linked to TeV scale physics are exciting due to
their testability in the near future. I will discuss some TeV scale
models, which provide a framework for understanding R-parity by
utilizing it’s connection to baryon minus lepton number symmetry(B-L).
I will also outline some possible collider implications of such
models.
Tuesday December 14 at 1:30pm
Tricia Vahle
William & Mary
New results from MINOS (slides pdf)
MINOS records interactions of neutrinos produced by the Fermilab NuMI
beam line in two detectors, 734 km apart. Comparisons of the energy
spectra and beam composition at the two sites yield precision
measurements of neutrino oscillations for L/E $\sim$ 500 km/GeV. In this
paper, updated results from an integrated exposure more than twice
that of earlier publications will be presented. We will present a
measurement of the probability of muon-neutrino disappearance as a
function of energy and of the neutrino oscillation parameters
\dmsq{32} and \sinsq{23}. We will report on the measurement of
neutral current interaction rates in each detector, which enables a
search for light neutrino families that do not couple via the weak
interaction. We will also discuss results from the search for
electron-neutrino events in the Far Detector, which probes the value
of the mixing angle $\theta_{13}$. Finally, we will discuss a
dedicated antineutrino run, which allows for measurement of
antineutrino oscillation parameters.
Seminars in 2009
Tuesday January 20 1:30pm
Richard Van de Water
Los Alamos National Laboratory
Anti-Neutrino Oscillation Results from MiniBooNE (slides pdf)
The first MiniBooNE neutrino oscillation results published April of
2007 ruled out the simple two neutrino oscillation hypothesis of the
LSND experiment. However, MiniBooNE unexpectedly observes a
significant excess of electron-like events below a reconstructed
neutrino energy of 475 MeV. For the last two years MinibooNE has been
running in anti-neutrino mode. The anti-electron neutrino data sample
can shed light on the neutrino low energy excess since they share many
of the same backgrounds and systematic errors. As well, a search for
oscillation at higher energy can be performed. Updated results of the
neutrino low energy excess and new anti-neutrino oscillation results
will be presented.
Tuesday February 3 1:30pm
Melissa Jerkins
University of Texas at Austin
Neutrino physics using cold atoms (slides pdf)
Recent advances in atomic slowing and cooling are opening new avenues
through which to explore neutrino properties. I will discuss several
potential applications of these technologies to neutrino research,
including new concepts for tritium beta-decay and neutrino Mossbauer
experiments. The absolute mass scale of the neutrino has long been probed
through tritium beta-decay, but these technically challenging experiments
have so far been unable to detect the neutrino mass. By utilizing a slow,
cold beam of tritium atoms to create the tritium source, one could detect
both the helium ion and the beta, which implies that the neutrino mass
could be directly reconstructed. I will present simulation results and
discuss the feasibility of both a three-body tritium beta-decay experiment
and a boundstate tritium beta-decay experiment. I will also discuss
preliminary explorations of a neutrino Mossbauer experiment in which
advances in magnetic slowing of atoms allow trace detection of tritium
created in recoilless reverse tritium beta decay. Observation of the
Mossbauer effect with neutrinos would be an exciting first step
toward tabletop neutrino oscillation experiments.
Tuesday February 10 1:30pm
Francesco Polci
LAL Orsay
Searching for the Higgs boson with ATLAS (slides pdf)
The beginning of the operations of the Large Hadron Collider is a
crucial event for particle physics. The LHC will allow to explore a very
large mass region where we expect to find the Higgs boson, a fundamental
brick in particle physics theories.
Waiting for collisions, ATLAS prepares the searches for the Higgs boson
both in the Standard Model and in the supersymmetric theoretical
frameworks. The different channels studied, the analysis techniques and
the most recent estimations of the discovery potential will be
presented, with a particular focus on the analysis of the disintegration
of the Higgs into a pair of photons.
Tuesday March 17 1:30pm
Bryan Fulsom
University of British Columbia
Radiative Decays of the X(3872) in BaBar
The X(3872) was the first of many puzzling new heavy quarkonia states to
be discovered in the B Factories. Yet after six years of study, the
questions regarding its internal structure remain unsolved. Is it a
conventional charmonium state, or does it represent something more
exotic, such as a four-quark molecule?
In this talk, I will review the experimental evidence for the X(3872)
and discuss how radiative decays to ccbar gamma could prove important in
solving this mystery. I will present the results of the search for
decays of the X(3872) to J/psi gamma and psi(2S) gamma using the full
BaBar dataset, and discuss their impact on our understanding of the
X(3872).
Tuesday March 24 1:30pm
Professor Gabriella Sciolla on behalf of the DM-TPC collaboration
MIT
DM-TPC: a novel apparatus for directional Dark Matter detection (slides pdf)
Directional detection is key to provide unambiguous observation of
dark matter even in the presence of insidious backgrounds.
The DM-TPC collaboration is developing a TPC with optical readout
with the goal of detecting the sense and direction of the elastic
recoils generated by Dark Matter interactions. The detector, filled
with CF_4 gas at low pressure, is equipped with a mesh-based
amplification region that allows for 2D imaging of the recoils in a
CCD camera. The third coordinate of the recoil is provided by PMTs.
The sense of the direction is determined by measuring the energy loss
along the recoil track.
The performance of this detector has been studied using alpha
particles, low-energy neutrons, and x-rays. Results from a first
prototype clearly demonstrated the suitability of this approach to
measure directionality by observing the “head-tail” effect for low-
energy nuclear recoils.
Two 10-liter prototypes of the DMTPC detector have recently been
built, and are ready to be moved to an underground laboratory for a
one-year run in 2009. A larger (1m^3) detector is also being
designed. A one-year underground run with such detector will allow us
to improve the current sensitivity on spin-dependent interaction on
protons by about a factor 50.
Tuesday May 1 1:30pm
Andrew Brandt
University of Texas, Arlington
Forward Protons from the SPS to the LHC
This seminar gives an overview of diffractive physics at hadron
colliders, focusing on proton detectors from the early days of hard diffraction at the SPS to the new joint ATLAS/CMS FP420 project designed to use diffraction as a tool to measure properties of the Higgs Boson.
Wednesday May 6 1:00pm
Robert Knapik
Colorado State University
The Cosmic Ray Energy Spectrum Measured by the Pierre Auger Observatory
The origins of comic rays with energies greater than 1018 eV are very
uncertain. This talk highlights comic ray detection with emphasis given
on how the energy of an event is determined, specifically, on how the
atmosphere is used as a calorimeter. The Pierre Auger Observatory was
able to take data during construction but was only fully completed last
summer. Already Auger has accumulated more data than all previous
experiments combined. The energy spectrum measured by Auger is compared
with previous experiments and the systematic differences that exist
between measured spectra are discussed. The energy spectrum, along with
arrival direction studies and primary particle identification, are used to
constrain models for the sources of high energy cosmic rays. The
astrophysical implications of the early Auger results and the next steps
for the Observatory are presented.
Tuesday September 1
Tae Min Hong
University of California, Santa Barbara
Looking for patterns in B-meson decays with baryons at BaBar
Tuesday September 22 at 1:40pm
Tom Schwarz
University of California, Davis
Top Quark Production at the Tevatron (slides pdf)
The Tevatron has now produced over 10 times the statistics since the
discovery of the Top quark over a decade ago. During this time,
measurement techniques have advanced at a rapid pace. The large
statistics collected and new advanced methods allow us to finally test
the top quark’s place in the Standard Model. I will present the
state-of-the-art in measuring top quark production, which includes the
two most precise measurements of the top quark cross section in the
world. I will also present the combined top quark cross section for
several measurements in all channels at CDF. The result is the most
precise determination of the rate of top quark production to date. In
addtion to discussing the top cross section, I present a measurement
of the forward backward asymmetry in top production. This measurement
is a test of discrete symmetries at very high energy, which has
recently received a sizable amount of attention because of an
unexpectedly large measured value.
Tuesday September 29 at 1:40pm
Sarah Eno
University of Maryland
Early searches for exotic physics, beyond the standard model, with CMS (slides pdf)
The LHC is scheduled to commence running this fall, and should at
sometime during the run become the world’s new high-energy frontier.
Many models of physics beyond the standard model, such as those with
extra dimensions, can produce spectacular “exotic” signatures with
large rates that could be detected with even a small amount of
high-energy data. In this talk, I discuss preparations and projected
reach for these searches from the CMS collaboration for the upcoming
run.
Tuesday October 6 at 1:40pm
Eva Halkiadakis
Rutgers University
Direct measurement of the W boson production charge asymmetry at CDF (slides pdf)
I will present the first direct measurement of the W production charge asymmetry as a function of the W boson
rapidity y_W in p-pbar collisions at the Tevatron. I use a sample of W->e nu events in data from 1 fb-1 of
integrated luminosity collected using the CDF II detector. In the region | y_W | < 3.0, this measurement is capable
of constraining the ratio of up- and down-quark momentum distributions in the proton more directly than in previous
measurements of the asymmetry that are functions of the charged-lepton pseudorapidity.
Tuesday October 13 at 1:40pm
Gustaaf Brooijmans
Columbia University
Breaking the Electroweak Barrier: Novel Signatures at Hadron Colliders (pdf slides)
The search for physics beyond the standard model will be the main focus
of the experiments at the LHC. We have precious little information on
the nature of any new physics however, and will need to explore a large
variety of signatures in our exploration of the multi-TeV energy domain.
One interesting possibility is that new physics will manifest itself
in the decays of heavy objects to top quarks or W and Z bosons. This
will lead to novel experimental signatures which will be discussed in
this seminar.
Tuesday October 27 at 3:30pm in A8 (colloquium)
Evelyn Thomson
University of Pennsylvania
Smashing particles at the High Energy Frontier (pdf slides)
Experimental particle physics seeks to understand the fundamental
particles and interactions of the universe. I will present the status
and future prospects of experimental knowledge for two of these
particles: the top quark, the most massive fundamental particle with
approximately the same mass as a gold nucleus comprised of 200
nucleons; and the Higgs boson, the most elusive particle as it has
evaded detection for over forty years! The results that I will present
are based on analysis of data from the current run of the
CDF experiment at Fermilab, which began in 2001 and is expected to
continue through 2010. In order to produce massive particles like the
top quark, Einstein’s famous relation E=mc2 tells us that a lot of
energy is needed. Therefore, a beam of protons is accelerated to close
to the speed of light and then brought into collision with another
equally energetic beam moving in the opposite direction. These
collisions occur 1.7 million times per second, and I will discuss how
the debris from these collisions is examined for clues about the
properties of particles like the top quark and the Higgs boson.
The prospects for the future are dominated by the next generation
CERN Large Hadron Collider, located near Geneva in Switzerland, which
will reach collision energies up to seven times higher than the
Fermilab Tevatron. In preparation for the first year-long run of the
Large Hadron Collider beginning in November 2009, I will also describe
the commissioning of the Transition Radiation Tracker, an important
part of the giant ATLAS experiment. The Transition Radiation Tracker
is essentially a camera with 350,000 channels that takes 75
nano-second long snap-shots of the trajectories of electrically
charged particles. The radius-of-curvature of a charged particle’s
trajectory in a strong magnetic field allows determination of the
particle’s momentum, while the 100 times brighter signal from
transition radiation allows partial discrimination of the least
massive charged particle, the electron, from other more massive
charged particles.
Tuesday November 17 at 1:40pm
Paul Sorensen
Brookhaven National Laboratory
Recent results with the STAR detector at RHIC
Tuesday November 24 at 1:40pm
Justin Keung
University of Pennsylvania
Search for WZ in the lvbb final state at CDF (slides pdf)
Tuesday December 1 at 1:40pm
Valerie Halyo
Princeton University
CMS Luminosity Monitors and Standard Candles (slides pdf)
Tuesday December 8 at 1:40pm
Gabriel Orebi Gann
University of Pennsylvania
New results from SNO (slides pdf)
Seminars in 2008
Friday January 11 1:30pm
Dr. Dmitri Tsbychev
State University of New York, Stony Brook
Looking for new physics in the Bs-meson system
Slides (pdf)
The D0 experiment at the Fermilab Tevatron collider has collected large
samples of hadronic and semileptonic decays of Bs mesons,
in which comprehensive studies were performed to search for evidence of
physics beyond the Standard Model.
We present the latest results on the measurement of mixing parameter dMs
and the width difference between heavy and light Bs-meson states
as well the latest results on indirect CP violation in the Bs meson
system at D0.
Thursday January 17 1:30pm
Dr. Chunhui Chen
University of Maryland
The Measurement of CP Violation Parameter Beta and
Search for the New Physics from Babar Experiment
Slides (pdf)
In the Standard Model, quark mass, their mixing and CP violation
have a common origin, the spontaneous electroweak symmetry breaking
due to the Higgs boson. Studying CP violation and flavor-changing
interactions not only probes the electroweak scale, but also provides
an excellent laboratory for us to search new physics beyond the
Standard Model. In this talk, I will present the most recent measurements
of CP violation in the B meson decays from Babar experiment. The
main focus of the talk will be the determination of the
Cabibbo-Kobayashi-Maskawa (CKM) phase: beta. I will also discuss
the implication of the results of CP violation
in B decays for the Standard Model and some of its extension.
Tuesday January 22 1:30pm
Dr. Eliot Lipeles
University of California, San Diego
The Search for the Higgs and Diboson Production at the Energy Frontier
Slides (pdf)
At the core of the standard model of particle physics is the mechanism of
electroweak symmetry breaking. The key ingredient of this mechanism,
the Higgs boson, has yet to be seen. I present a search for the Higgs decay
to the WW final state and measurements diboson production which is sensitive
to the electroweak symmetry breaking predictions for the couplings between
gauge bosons.
Thursday January 24 1:30pm
Dr. Florencia Canelli
Fermi National Accelerator Laboratory
Towards an understanding of electroweak symmetry breaking
Slides (pdf)
The top quark offers a powerful window to understanding physics at
the electroweak scale. Through the precision measurement of its
mass, we are directed to the mass of the Higgs boson, the physical
manifestation of the standard
model explanation for electroweak symmetry breaking. Through its
single-top production, as opposed to the more
common QCD production, we learn about electroweak production of the
heaviest quark, and we provide a stepping
stone to Higgs boson production in the same topology. Through study
of the top quark decay couplings, we test for
new higher energy scale deviations from the standard model
electroweak interaction. In this talk, I will highlight the
rich physics of the top quark, and its significance in understanding
electroweak scale physics.
Tuesday January 29 1:30pm
Dr. Alexandre Telnov
Princeton University
Recent progress in CP violation: New Physics under siege
Slides (pdf)
Just eight years ago, the dominant role of the Kobayashi-Maskawa mechanism of CP
violation in low-energy flavor-changing processes was merely a credible
hypothesis. Started in 1999, the asymmetric B-meson factories at SLAC and KEK
rapidly established CP violation as one of the inalienable features of the
Standard Model (SM) through the study of the B0 decays driven by the tree-level
b -> c c-bar s transition. Then, they took advantage of their spectacular
success in reaching luminosities well above the design values by unleashing an
attack on the SM of unprecedented breadth, precision and vigor.
Indeed, nearly
all SM extensions provide multiple new sources of CP and flavor violation, which
in general could lead to significant deviations from SM predictions in B-meson
decays. Particularly sensitive to New Physics are the processes driven by
flavor-changing neutral currents (FCNCs), which are strongly suppressed in the
SM by the small CKM angles and the GIM mechanism; various
SM extensions would require highly specialized flavor structures to achieve
similarly effective FCNC suppression. Any statistically significant deviation
from the SM predictions would mean the end of Standard Model’s reign; lack
thereof provides unique information about TeV-scale physics and, with the
increasing precision of B-factory measurements, greatly constrains the parameter
spaces of the favorite SM extensions.
A brief historical and theoretical introduction to CP violation and its
significance to cosmology will be followed by a review of the experimental
techniques employed at B-meson factories to make precise measurements of
CP-violating quantities and to search for signs of physics beyond the SM. We
will review the measurements performed by the BaBar and Belle experiments where
CP violation has been firmly established, and discuss how recent advances in
harnessing the full particle-identification power of the BaBar detector have
helped pave the way to the observation of CP violation in the time distribution
of B0 -> pi+pi- decays and direct CP violation in B0 -> K+pi-. In conclusion,
we will recap the current experimental status of CP violation and the Standard
Model, and take a glimpse at their future.
Tuesday February 5 1:30pm
Dr. Andy Haas
Columbia University
The Search for the SM Higgs Boson at D0
Slides (pdf)
Discovery of the Higgs boson would verify the final piece of the
Standard Model. The Higgs boson is needed to explain how the W and Z
bosons of the weak force acquire mass and to consistently give masses to
the fermions. Using the D0 detector at the Fermilab accelerator, our
group is progressing in our hunt for this elusive new particle.
Particular decay channels will be highlighted, and some of the advanced
analysis methods and tools developed for the search will be discussed in
detail. Finally, the projected sensitivity for the next two years and a
few techniques that will help to achieve this sensitivity will be shown.
Tuesday 25 March 1:30pm
Dr. Vadim Rusu
Wilson Fellow at Fermi National Accelerator Laboratory
From Collisions to Publication: A Higgs Story (Slides pdf)
For more than 30 years the Standard Model of Particle Physics
provided a solid framework for explaining the experimental
observations of the last decades. A fundamental piece is missing and
that is the origin of mass. Within the Standard Model, the mass of
fundamental particles is given by their interaction with the Higgs
field. The quanta of this field is the Higgs boson. The experimental
observation of the Higgs particle is an essential part of our
particle physics program and may provide us with clues about new
physics beyond the realm of the Standard Model. I will show the
experimental progress towards this goal at CDF, one of the two
experiments at Tevatron, the world’s largest collider currently in
operation. The presentation will overview all aspects of this
progress, from detector and data collection improvements to new
analysis strategies.
Tuesday 1 April 1:30pm
Dr. Chris Neu
University of Pennsylvania
Measurement of W+b-jets at CDF (pdf)
Tuesday 15 April 1:30pm
Dr. Anadi Canepa
University of Pennsylvania
Tau leptons at CDF (pdf)
Tau leptons are unique in the Standard Model.
Thanks to a large coupling to the Higgs boson, they might shed light on
the electroweak symmetry breaking. Tau leptons are also an exciting window
into New Physics. SUSY predicts abundance of taus in charged
Higgs decays. Taus processes are enriched in Right-Left Symmetric Models with double charged Higgs,
while new massive gauge bosons can undergo lepton flavor violating decays.
CDF established its tau reconstruction technique measuring the W → τ ν and Z → τ+ τ–
cross sections and it is now exploring the pp collisions at Tevatron looking for new phenomena.
The challenge of reconstructing taus at hadron colliders and the
latest results of tau physics at CDF are reported.
Thursday 17 April 4pm Room A8
Emeritus Professor James Cronin
University of Chicago
Study of the Highest Energy Cosmic Rays with the Pierre Auger Observatory
Tuesday 22 April 1:30pm
Professor Joe Boudreau
University of Pittsburgh
sin 2 βs at CDF
While CP violation in B0 and B+ decays has been extensively
investigated at B-factories over the last decade, corresponding
knowlege in the B0s system has been lacking. B0s mesons, which
are not produced in B factories at the Upsilon(4S) are produced
with large cross section at the Tevatron collider. Following the
measurement of the B0s to B0s oscillation frequency in 2006,
the CDF experiment has now investigated CP asymmetries in B0s
meson decays. We report on the very first flavor-tagged analysis of
about 2,000 B0s decays to J/ψ φ, reconstructed in
1.35/fb of data. This channel is sensitive not only to the
width difference Delta Γ in the B0s system but also to to
βs, the angle of the “squashed” (bs) unitarity triangle. We
report a confidence region in the two dimensional space of 2βs
and Delta Γ. The data is consistent with the standard model
prediction at the 15% confidence level, corresponding to 1.5 Gaussian
standard deviations.
Monday June 2 3W2 1:30pm
Sinead Farrington
University of Oxford
Rare B decays at CDF
Monday June 16 3W2 1:15pm
Chunlei Liu
University of Pittsburgh
The measurement of a small angle — Search for CP violation in B0s system at CDF
CKM mechanism has been established well since the first CP violation
discovery in 1964. To search for New Physics, it’s useful to compare
tiny CP violation prediction from Standard Model with experimental result.
The B0_s-> J/psi phi channel provides such an ideal place where the
CP phase is predicted to be nearly zero. At CDF, we are able to
reconstruct about 2000 signal events with 1.35 fb-1 data. The final
result we obtained is a confidence region in the CP phase and decay width
difference space which shows an intriguing deviation (1.5 sigma) of the Standard Model.
Thursday August 7 1:30pm
Mr. Joe Tuggle
University of Maryland
Searching for New Physics in Radiative Penguin Decays at BaBar
Friday August 8 1:30pm
Mr. Rustem Ospanov
University of Texas at Austin
A measurement of muon neutrino disappearance rate with the MINOS detectors and the NuMI neutrino beam
Monday August 11 3:30pm
Mr. Brandon Parks
Ohio State University
Search for the Standard Model Higgs Boson at CDF Run II
Tuesday August 12 3:30pm
Mr. Sourabh Dube
Rutgers University
Search for Supersymmetry at CDF using the Trilepton signature
Tuesday October 28 1:30pm
Sasha Pranko
Fermi National Accelerator Laboratory
Physics with Photons at CDF (slides pdf)
Photon production in hadronic interactions is one of the most common processes. In fact, high energy photons are only outnumbered by jets. They are also present
in many well motivated theoretical models of new physics beyond the Standard Model. Measurements with final state photons have many advantages. Photons couple to any
particles with electric charge. Being stable particles, they do not suffer a sensitivity
loss from branching ratios. Photon’s energy and direction are well measured.
In my presentation, I will talk about photon reconstruction at CDF, including photon
identification, fake rates, and background subtraction techniques. In the second part
of my talk, I will focus on searches for new physics in final states involving photons,
jets, and missing transverse energy.
Tuesday November 11 1:30pm
Edgar Carrera
Florida State University
Search for extra dimensions with a single photon and missing transverse energy at D0 (slides pdf)
The enormous amount of fine-tuning that the Standard Model requires to
salvage its validity at higher energy regimes is one of the most
embarrassing aspects of our ignorance about the physical laws of Nature.
Theories with large extra dimensions (LED), where gravitons can escape
our 3-dimensional world, have been proposed as an alternative method to
solve this problem. As a test for these hypothetical space
configurations, I will present a D0 search for the direct production of
Kaluza Klein gravitons in association with single photons. Special
emphasis will be given to photon identification and the difficult task of
rejecting backgrounds to these final states.
Thursday November 13 1:30pm note in room 2C8
Mark Hartz
University of Pittsburgh
Measurement of the B_c Meson Lifetime at CDF Using B_c->J/psi+l+X Decays
The B_c meson is an unique laboratory for studying QCD since it consists
of two heavy quarks and decays via the weak interaction, allowing for
the study of the weak decay properties in the framework of
non-relativistic QCD. I review a measurement of the B_c lifetime at
CDF using semileptonic B_c decays to J/psi particles and leptons. The
result is compared to previous measurements of the B_c lifetime, and the
measured quantities are used while discussing possible constraints on
the theoretical predictions of the lifetime.
Tuesday November 25 1:30pm
Mitch Newcomer
University of Pennsylvania
Upgrading the ATLAS Detector for Super LHC (pdf slides)
The Large Hadronic Collider (LHC) will begin operation in the spring of
2009. The Two large detector systems, ATLAS and CMS built to search for
the Higgs Boson and explore the limits of the Standard Model are
arguably the most complex instruments ever constructed, each exploiting
the effort a nearly a thousand scientists and engineers and taking more
than 10 years to design and build. These detectors were envisioned for
a useful life of ten years at the expected luminosity of 10^33
protons/cm^2. An upgrade to the accelerator planned for 2015 will
greatly enhance the reach for experimenters to explore rare processes by
increasing the luminosity by a factor of ten. This higher rate will
require upgrading several detector sub-systems in each major detector,
improving their rate capability and increasing their radiation
tolerance. It is hoped that the system upgrade can be accomplished in
the next five to seven years by taking advantage of the experts and
infrastructure developed to complete the first generation detectors.
Penn’s successful involvement the development of detector mounted front
end electronics for the ATLAS detector has led to the opportunity to
take a leading role in this upgrade. Work on the choice of technology,
architecture and in the development of Front End Electronics for silicon
strip and calorimeter electronics will be presented.
Tuesday December 2 1:30pm
Trevor Vickey
University of Wisconsin
Searching for New Physics in High-pT Di-tau Final States with the ATLAS Experiment at the LHC (slides pdf)
A number of non-Standard-Model physics processes can lead
to events with tau lepton pairs in the final state. I discuss the
potential for the ATLAS experiment at the Large Hadron Collider (LHC)
to observe high-mass resonances that decay into two oppositely-charged
taus. The prospects for discovering an extra gauge boson, $Z’$, with
a mass between 600 and 2000 GeV are presented and the application of
this study to graviton and heavy MSSM Higgs boson searches is also
discussed.
Tuesday December 9 1:30pm
Abid Patwa
Brookhaven National Laboratory
Search for MSSM Higgs Boson Production in di-tau final states at D0 (slides pdf)
Recent results from the D0 Experiment at the Fermilab Tevatron collider
are presented on the search for the production of neutral Higgs bosons
decaying into di-tau final states. In particular, searches with
integrated luminosities of up to 2.2 fb-1 of data are described in both
the Higgs decaying into tau pairs as well as those produced in association
with a b-quark. Since no significant excess is observed over the
predicted backgrounds in either decay mode, limits on its production cross
section times branching ratio are set for Higgs masses within the range
from 90 to 300 GeV. The results are subsequently interpreted in the
Minimal Supersymmetric Standard Model (MSSM) and regions in the (mA,
tan(beta)) parameter space for different MSSM benchmark scenarios are
excluded at the 95% C.L. Future prospects for measurements with increased
integrated luminosities delivered by the Tevatron are also discussed.
Seminars in 2007
Friday March 23
Teh Lee Cheng
Royal Holloway, London
Search for production of single top quarks via flavour-changing neutral
currents with the ATLAS detector.
I present the search for anomalous production of single top quarks
via flavour-changing neutral currents (FCNC) with the ATLAS
detector at the LHC. The signal is u/c + g -> t.
Top quark FCNC coupling with a gluon is extremely
small according to the Standard Model. However, new physics models
usually allow large enhancements to this coupling, which
may can be many orders of magnitude larger. A cut-based analysis
is developed and the result shows that, with an
integrated luminosity of 10 fb-1, equivalent
to one year of LHC running at a tenth of the design luminosity,
ATLAS starts to reach the required sensitivity to test predictions of
some of the new physics models.
Tuesday April 3
Peter Wagner
Texas A&M
Search for Heavy, Neutral, Long-Lived
Particles that Decay to Photons at CDF
Searches for events with final state photons and missing transverse
energy (MET) at collider experiments are sensitive to
new physics from a wide variety of models including gauge
mediated supersymmetry breaking (GMSB). In these models
the lightest neutralino (chi_10) decays into a photon and a
weakly interacting, stable gravitino that gives rise to MET
by leaving the detector without depositing any energy. The observation
of an ee+photon+photon+MET candidate event by the CDF experiment during Run I
at the Fermilab Tevatron has increased the interest in
experimental tests of this class of theories. Most subsequent searches
have focused on promptly produced photons,
however the chi_10 can have a lifetime on the order of nanoseconds or
more. In this talk I present the results of the first search for heavy,
long-lived particles that decay to photons at a hadron collider using the
newly installed EMTiming system at CDF to identify chi_10 candidates by
virtue of their producing photons with a “delayed” arrival time.
Tuesday April 10
Huaizhang Deng
University of Pennsylvania
Discovery of Solar Neutrino Oscillations
Monday April 16
Sasa Fratina
Jozef Stefan Institute
Measurement of CP Violation in B0 -> D+D- Decays
I will report on the recent measurements of the branching fraction and CP
violation parameters in B0 -> D+D- decays. The decay time distribution of
these decays is sensitive to the angle of the Cabibbo-Kobayashi-Maskawa
(CKM) quark mixing matrix phi_1 (beta) and offers another opportunity to
test the unitarity of the CKM mixing matrix and search for possible new
physics contributions to these decays. The results to be shown are based
on a large data sample of more than 500 x 10^6 BBbar pairs collected with
the Belle detector at the KEKB asymmetric-energy e+e- collider. We find
evidence of CP violation in B0 -> D+D- at the 4.1 sigma confidence level.
While the result for the CP violation parameter S is consistent with
expectations from other measurements, the value of the parameter A favors
large direct CP violation at the 3.2 sigma confidence level, in
contradiction to Standard Model expectations.
Tuesday April 17
Sylvie Brunet
University of Montreal
|Vub| measurements at BaBar
The BaBar experiment, located at the Stanford Linear Accelerator Center
(SLAC), produces millions of B mesons. The decay of the B mesons can be
used to measure many elements of the Cabibbo-Kobayashi-Maskawa (CKM)
matrix, which quantifies the quarks’ flavor changing probabilities. One of
the important elements is |Vub|. Its value is not predicted by the
Standard Model. Its measurement is a critical constraint on the Unitarity
Triangle, and thus, on the Standard Model itself. Our knowledge of |Vub|
comes from measurements of the small B -> Xu l nu decay rates where a “b”
to “u” quark transition is present. The precision on |Vub| is limited in
large part by the uncertainties in the non-perturbative QCD calculations
(form-factor) that are used to extract |Vub| from the measured decay
rates. In this talk, I will concentrate on the recent measurement of B ->
pi0 l nu decays using semileptonic tags at BaBar. From this study, a
total branching fraction and partial branching fractions in three bins of
q^2, the invariant mass squared of the lepton-neutrino system are
reported. This allows us to evaluate |Vub| and to compare the measured
form-factor spectrum, in three bins of q^2 with different theoretical
predictions. I will also summarize the state of the art of the |Vub|
measurements obtained at the B factories.
Wednesday April 18
Hirohisa Tanaka
Princeton University
First Results from MiniBooNE
This seminar reports the initial results from a search for muon neutrino to electron neutrino oscillations by
the MiniBooNE (Mini Booster Neutrino Experiment) Collaboration. MiniBooNE was motivated by the result from the LSND
experiment which presented evidence for neutrino oscillations with a mass-squared difference of O(1 eV^2/c^4).
The MiniBooNE experiment uses a high-intensity neutrino beam with an average energy of ~800 MeV produced
by protons from the Booster accelerator at Fermilab. The detector is a 800 ton sphere of mineral oil instrumented
with 1520 photomultiplier tubes positioned 540 meters from the production target. The detector identifies and classifies
neutrino events via the Cherenkov and scintillation light produced by particles emerging from the neutrino interactions.
The results of this analysis use the neutrino-mode data set corresponding to 5.58×10^20 protons on target.
Wednesday April 25 Fisher-Bennet Hall, 3340 Walnut
Franklin Medal Symposium
schedule
Monday April 30
Brian Connolly
Columbia University
Probing the High Energy Universe the Ultrahigh Energy Cosmic Rays
The High Resolution Fly’s Eye Experiment (HiRes) in Utah is an
air fluorescence telescope mapping the northern sky in cosmic rays
at energies above 10^18 eV. From December 1999 to March 2006 HiRes
operated in stereo mode, i.e. with two sites separated by 13 km to
provide cosmic ray data of unprecedented quality of the northern sky.
We focus on the latest results from the monocular and stereoscopic
data concerning the primary chemical composition above 10^18 eV
and the observation of the GZK cut-off.
Tuesday 18 September A5 3:15pm
Dr. Bernd Stelzer
University of California, Los Angeles
Search for Single Top Quark Production at CDF
Slides (ppt) and pdf (no animations)
In 1995, the CDF and D0 collaborations at the Tevatron collider at Fermilab
discovered top quarks that were produced in pairs via the strong
interaction.
The top quark was measured to be the heaviest elementary particle of the
Standard Model. Ten years after the top quark discovery, many things remain
unknown about its properties. In this talk, I will present recent evidence
for electroweak single top quark production. This alternative mechanism of
producing top quarks at the Tevatron is experimentally very challenging to
measure but allows the direct determination of the CKM matrix element
|Vtb|.
Wednesday 17 October A2 3:30pm
Dr. Ulrich Husemann
Yale University
Search for Flavor-Changing Neutral Currents in Top Quark Decay at CDF
Slides (pdf)
Flavor changing neutral current (FCNC) interactions are heavily
suppressed in the standard model of particle physics, but are expected
to be enhanced in the presence of new physics. Searches for FCNC
interactions are therefore excellent probes of physics beyond the
standard model. The suppression of FCNC interactions is especially
strong in the top quark sector. The standard model predicts branching
fractions for top quark FCNC decays far below the reach of experiments
at the Fermilab Tevatron and even at the Large Hadron Collider
currently under construction at CERN. I will present the first search
for the FCNC decay t→ Zq during Tevatron Run II using data recorded
with the CDF II detector between March 2002 and September 2006.
Tuesday 30 October A5 3:15pm
Prof. Daniel McKinsey
Yale University
New results from the XENON10 dark matter search
Slides (pdf)
The XENON10 experiment is a search for dark matter in the form
of Weakly Interacting Massive Particles (WIMPs). The XENON10 detector
uses the simultaneous measurement of ionization and scintillation in
liquid xenon to distinguish between nuclear recoils (due to WIMPs or
fast neutrons) and electron recoils (due to gamma rays). Ionization
electrons are extracted into the xenon vapor where they produce a large
proportional scintillation signal in a grid assembly. Both prompt and
proportional scintillation light are detected by PMT arrays on the top
and bottom of the active liquid xenon volume. The distribution of
proportional scintillation light in the top PMT array can be used to
achieve xy position resolution, while the ionization drift time gives
position resolution in the z direction. This allows the definition of a
low-background fiducial volume. XENON10 was installed in the underground
Gran Sasso National Laboratory in Italy in March 2006, and a blind
analysis was performed on data acquired between November 2006 and
February 2007. I will present the results of that analysis, which has
resulted in the most sensitive limit to date on the spin-independent
WIMP-nucleon scattering cross-section. I will also describe LUX, a new
dark matter experiment using the same technology, planned for
2008-2009.
Tuesday 13 November A5 3:15pm
Dr. Conor Henderson
Massachusetts Institute of Technology
Global Search for New Physics at CDF
Slides (pdf)
The Standard Model of particle physics is widely believed to
be incomplete, but as yet there are no clear indications as
to what form the new electroweak scale physics might take.
Rather than focusing on particular new physics scenarios,
we present a new approach where the entire high transverse
momentum data collected by the CDF detector at the
Fermilab Tevatron are searched for discrepancies relative
to the Standard Model prediction.
A model-independent approach (Vista) considers the bulk
features of the data, and a quasi-model-independent technique
(Sleuth) focuses on the high-pT tails. Results of this global
search for beyond Standard Model physics will be presented.
Tuesday 27 November A5 3:15pm
Prof. B. Lee Roberts
Boston University
Proposal for a new muon g-2 experiment
Slides (pdf)
The muon (g-2) experiment at the BNL AGS reached a relative precision of
0.5 parts per million on the muon anomalous magnetic moment.
Thanks to recent data from electron-positron
annihilation to hadrons, the standard-model prediction has reached
the same level of precision. When compared, the two differ by
3.4 standard deviations. Since the muon anomaly is sensitive to
a wide range of physics beyond the standard model, agreement or
difference with the standard-model will be important in
constraining interpretations of discoveries that will be
made at the LHC. The experiment and theory will be reviewed,
and possibilities for improving both values will
be discussed, along with the implications for LHC data.
A recent review of theory and experiment can be found in
hep-ph/0703049, published in Reports on Progress in Physics, {\bf 70},
(2007) 795-881
The non-standard model reach is discussed in arXiv:0705.4617 [hep-ph]
Tuesday 11 December 2N36 1:30pm
Prof. Gregorio Bernardi
LPNHE, Universities Paris VI and VII, France
Search for the Higgs boson at D0
Slides (pdf)
The Higgs boson is the only particle of the standard model which has not
been discovered yet, but it might be the most important one. Indeed, it is
through the Higgs mechanism that all massive fundamental particles are expected to
acquire their mass. Hence the search for the Higgs boson has been one
of the major activities of Elementary Particle Physicists during this
last decade. In this seminar, we will introduce the physics of the Higgs
boson and report on the experimental searches which are currently being
done at the Tevatron by the D0 experiment, and on the combined results
obtained by CDF and D0. We will conclude on the prospects of Higgs discovery
in the coming years.
Seminars in 2006
January 11 2006 – Department Colloquium
Young-Kee Kim
Co-spokesperson of CDF and new Deputy Director of Fermilab
University of Chicago
E=mc2 Opening Windows on the World
slides (pdf)
January 17 2006
Masahiro Morii
Harvard University
B physics beyond CP violation: Semileptonic B decays
January 24 2006
Carsten Krauss
Queens University
The PICASSO dark matter experiment
February 7 2006 Penn-Princeton joint seminar @ Penn
Pier Oddone
Director of Fermi National Accelerator Laboratory
Fermilab and High Energy Physics
March 1 2006 – Department Colloquium – Primakoff Lecture
Paul Langacker
University of Pennsylvania
The Standard Model and Strings – Can They be Connected?
slides (pdf)
March 14 2006
Kyle Cranmer
Brookhaven National Laboratory
Prospects for the Higgs at the LHC
April 4 2006
Anadi Canepa
Purdue University
Chargino and Neutralino in the Golden Channel at CDF
April 11 2006
Dave Casper
University of California, Irvine
A long-baseline oscillation experiment using a radioactive ion storage ring (“beta-beam”)
slides (pdf)
April 25 2006
Veronica Sorin
Michigan State University
CDF Trigger System at World Record Luminosities & Test of Electric Charge of the Top Quark
May 2 2006
Richard Hughes
Ohio State University
GLAST: Science in Flight
May 3 2006 – Special Department Colloquium
Joe Kroll
University of Pennsylvania
Matter-Antimatter Transformations at 3 Trillion Hertz
May 9 2006
Karen Gibson
Carnegie-MellonUniversity
Measurement of Relative Fragmentation Fractions of B hadrons at CDF
September 11 2006
Katherine Copic
University of Michigan
A New Measurement of the Ratio of W and Z Production at CDF
Electroweak physics at Fermilab is entering an era of new precision. With
benchmark analyses completed, we are investigating new approaches to get the
most out of our expanding data samples. I will present a new method for
measuring the ratio of W and Z production at the Tevatron’s center-of-mass
energy of 1.96 TeV. This measurement can be used to extract the indirect width
of the W boson and, therefore, the CKM matrix elements. For this analysis, a
combined sample of W and Z boson candidates is selected by requiring at least
one charged lepton and low net hadronic activity. The Missing Transverse Energy spectrum of the events is used to infer the relative rate of W and Z bosons. I
will show a preliminary measurement of this ratio using data collected with the CDF detector, and discuss future prospects.
September 12 2006
Alexander Brandt
DESY
Photoinjectors: Automated Signal Calibration of Probeless Resonators
The accelerating field inside photoinjectors is required to be stable in phase
to less than one degree. Field-symmetry considerations as well as difficulties
in routing channels for cooling water put the mounting of a field probe into
question. An alternative is to deduce the field from the incident and reflected
wave from the resonator, which demands for a precise calibration of the
channels. In this presentation, basic resonator theory is illuminated in order
to deduce a method for an automated determination of these parameters, which
also provides detailed information about the coupling (beta) and nonlinear
properties of the sensors. The procedure, based on the investigation of resonant
circles has been successfully tested at the electron guns at FLASH and PITZ. It
is currently being implemented into FPGA-based controller of the FLASH electron
gun.
October 10 2006
Dr. Aart Heijboer
University of Pennsylvania
Observation of Strange Beauty Meson oscillations
We report the observation of Bs-Bsbar oscillations from a time-dependent measurement of the Bs-Bsbar oscillation frequency Delta ms. Using a data sample of 1 fb^-1 of p-pbar collisions at sqrt{s}=1.96 TeV collected with the CDF II detector at the Fermilab Tevatron, we find signals of 5600 fully reconstructed hadronic Bs decays, 3100 partially reconstructed hadronic Bs decays, and 61500 partially reconstructed semileptonic Bs decays. We measure the probability as a function of proper decay time that the Bs decays with the same, or opposite, flavor as the flavor at production, and we find a signal for Bs-Bsbar oscillations. The probability that random fluctuations could produce a comparable signal is 8 X 10^-8, which exceeds 5 sigma significance. We measure
Delta ms = 17.77 +- 0.10 (stat) +- 0.07 (syst) ps^-1
and extract
|Vtd/Vts| = 0.2060 +- 0.0007 (exp) + 0.0081 – 0.0060 (theory).
November 7 2006
Daniel Sherman
Harvard University
Top Quark Pair Production at CDF
November 14 2006
Jovan Mitrevski
Columbia University
Search for Electroweak Top Quark Production at D0
Electroweak production of the top quark has many attractive features.
One is that the cross section is proportional to |Vtb|^2 and thus
provides a test of the CKM matrix^s 3-generation unitarity. The
constraints on |Vtb| not assuming unitarity are weak. Another is that
it provides a way to probe the V – A structure of the weak
interaction. Because the top quark decays before it has time to
hadronize, it retains its polarization information, making it
available for study. Furthermore, because the top quark has such a
large mass, close to the scale of electroweak symmetry breaking, one
wonders if it has some special role in beyond the Standard Model
physics. Studying the electroweak interaction in single top
production is a good way to look for such beyond the Standard Model
effects. In this seminar I will discuss the search for electroweak
production of the top quark being undertaken by the D0 collaboration
at Fermilab. I will discuss our selection criteria and background
modeling, and I will focus in particular on the matrix element method
analysis currently under way using 1 fb-1 of data.
November 16 2006
Jed Biesiada
Princeton University
CP Violation in b -> d Penguins
Over the last few years, the B factories at SLAC, USA, and KEK, Japan, have
verified the Cabbibo-Kobayashi-Maskawa mechanism of CP violation in the
Standard Model through the study of tree-dominated decays of the B meson.
The focus of the B factories has now shifted to the search for signatures of
new physics beyond the Standard Model, particularly through the study of
flavor-changing neutral currents, which proceed through “penguin” diagrams
involving a virtual loop. These decays are suppressed in the Standard
Model, increasing sensitivity to new-physics effects but decreasing
branching fractions. Exploiting large and growing datasets, BaBar and Belle
have made many measurements in the penguin decays where a b quark
transitions to an s quark, observing hints of possible deviations from
Standard Model expectations in CP-violating measurements. In this talk, I
describe the observation and first CP asymmetry measurement in the
corresponding gluonic b-to-d penguins, which are further suppressed in the
Standard Model and have not been previously observed. The observation of
the decays B->K0K0bar and B->K0barK+ opens a new sector of enquiry for the B
factories. I will also describe the update to the BaBar muon detector using
Limited Streamer Tube technology.
November 21 2006
Dr. Gabriella Sciola
MIT
Searching for New Physics in Rare B Decays
The study of CP violation at the B factories allows us to perform
quantitative tests of the CP sector of the Standard Model. Accurate
measurements of the sides and angles of the Unitarity Triangle
determine the parameters rho and eta of the theory, while redundant
measurements of the same quantities allow us to probe physics
Beyond the Standard Model.
The recent measurements of the B_s mixing frequency at the Tevatron have
dramatically improved our knowledge of |V_td/V_ts|, the right side of the
Unitarity Triangle. This opens up a new opportunity for probing New
Physics through an independent determination of the same quantity. In this
talk, I will discuss how such a measurement can be made using rare B
decays, and show our recent results.
November 28 2006
Dr. Stan Majewski
Jefferson Lab
A concept of a dedicated PET imager for proton therapy facilities
November 29 2006
Alberto Belloni
MIT
Observation of Bs – Bsbar oscillations
The latest results on the measurement of the Bs-Bsbar oscillation
frequency using 1 fb-1 of data from ppbar collisions with the CDF II
detector at the Fermilab Tevatron are reported. The probability as a
function of proper decay time that the Bs decays with the same, or
opposite, flavor as its flavor at production, which is determined using
opposite-side and same-side flavour identification methods, is measured. A
signal consistent with Bs-Bsbar oscillations is found.
December 19 2006
James Degenhardt
University of Michigan
Recent Diboson Physics Results from the DZero Collaboration
Diboson physics is the regime of electroweak physics that concerns
itself with the production of two gauge bosons. Diboson measurements
allow for verification of the Standard Model, while at the same time
searching for evidence of new physics by measuring the coupling
strengths of gauge bosons to each other. The Tevatron, which is the
highest energy particle accelerator in the world, has been a rich
source of new diboson physics results. I will be presenting the latest
diboson physics results from the DZero collaboration, including the
first evidence for WZ production.
Seminars in 2005
September 13 2005
Daniel Whiteson
University of Pennsylvania
Precision Top Quark Mass Measurement in the Dilepton channel at CDF
September 27 2005
Dan Akerib
Case Western Reserve University
Looking for WIMPs in the Galactic Halo: The Cryogenic Dark Matter Search
slides (pdf)
October 11 2005
Jason Nielsen
Lawrence Berkeley National Laboratory
Search for the standard model Higgs Boson
November 1 2005
Chris Ainsley
Cambridge University
CALICE: a high precision calorimeter for the ILC
November 8 2005- Penn-Princeton joint seminar @ Princeton
Joe Lykken
University of Chicago and FNAL
Is Particle Physics Ready for the LHC?
November 15 2005
<! Aart Heijboer?–>
Aart Heijboer
University of Pennsylvania
Search for Bs mixing at CDF
slides (pdf)
December 6 2005
Volker Braun
University of Pennsylvania
Recent developments in String Theory Group at Penn – A Heterotic Standard Model
Seminars in 2004
Tuesday, January 13 2004 at 1:30 (2N36 DRL)
Huaizhang Deng
University of Pennsylvania
Final result of the muon g-2 experiement
Wednesday, January 21 2004 at 2:00 (2N36 DRL)
Jonathan Link
Columbia University
Future Measurements of sin^2 2theta_13 at Nuclear Reactors
Tuesday, March 16 2004 at 1:30 (2N36 DRL)
Christopher Stepaniak
University of Minnesota
Measurements of semileptonic B-meson decay at CLEO
Tuesday, March 30 2004 at 1:30 (2N36 DRL)
Dawn Williams
University of California at Los Angeles
From the Moon to the Mines: Radio Detection of EHE Neutrinos
Wednesday, April 7 2004 at 1:30 (3N6 DRL)
Veronique Boisvert
CERN
Holding the Weights of the Heavens: the ATLAS High Level Trigger
Seminars in 2003
Tuesday, March 18 2003 at 1:30 (2N36 DRL)
Chris Walter
Boston University
Oscillation Results From The K2K Experiment
Tuesday, March 25 2003 at 1:30 (2N36 DRL)
Scott Oser
University of Pennsylvania
Solar Neutrinos And Beyond: Where Do We Stand?
Tuesday, April 1 2003 at 1:30 (2N36 DRL)
Huaizhang Deng
Yale University
Measurement of g-2
Tuesday, April 8 2003 at 4:00, DRL A7
Sasha Glazov
University of Chicago
Measurement of $\epsilon’/\epsilon$ by KTeV collaboration
Tuesday, April 29 2003 at 1:30, DRL 2N36
Evelyn Thomson
Ohio StateUniversity
Top Quark Physics at CDF
Tuesday, October 7 2003 at 1:30 (3N6 DRL)
Daniel Whiteson
University of California, Berkeley
The electron-muon final state at D0: Top quark production and exotic physics
Seminars in 2002
Tuesday, Sep. 10 2002 at 1:30 (2N36 DRL)
Fred Gray
University of Illinois-Urbana-Champaign
Measuring and Interpreting the Anomalous Magnetic Moment of the Muon
Tuesday, Nov. 5 2002 at 1:30 (2N36 DRL)
Daniel McKinsey
Princeton University
CLEAN: Cryogenic Low Energy Astrophysics with Neon
Tuesday, Nov. 26 2002 at 1:30 (2N36 DRL)
Brian Humensky
Princeton University
SLAC E-158: A Precision Measurement of Parity Violation in Moller Scattering
Tuesday, Dec. 3 2002 at 1:30 (2N36 DRL)
Roman Fleysher
NYU
Search for Gamma Ray Emission from Galactic Plane with Milagro
Seminars in 2001
Tuesday Feb. 6 2001 at 1:30
Jon Urheim
University of Minnesota
Status of MINOS
Wednesday Feb. 14 2001 at 1:30
Joseph Formaggio
Columbia University
Searching High and Low for Exotic Particles at NuTeV
Friday, Feb. 23 2001 at 2:00 (2N36 DRL)
Akira Konaka
TRIUMF
A 2nd generation long baseline neutrino experiment – Neutrino program at JHF
Tuesday Feb. 27 2001 at 1:30
Dieter Zeppenfeld
University of Wisconsin
Weak Boson Fusion: A Tool for Higgs Boson Studies at the LHC
Monday Mar. 5 2001 at 12:45
Jordan Goodman
University of Maryland
New Results from Milagro
Tuesday, Mar. 2001 at 1:30
Tao Han
University of Wisconsin
Higgs/SUSY Searches at Future Colliders
Monday Mar. 26 2001 at 12:45
Viktor Zacekv
University of Montreal
Search for Neutralino Dark Matter and the PICASSO Project
Tuesday Apr. 10 2001 at 1:30
Sven Heinemeyer
Theoretical and experimental implications of the possible observation of Higgs bosons at LEP
Tuesday Apr 24 2001 at 1:30
Cenap Ozben
Brookhaven National Laboratory
Precise measurement of the positive muon anomalous magnetic moment at BNL
Tuesday May 1 2001 at 1:30
George Redlinger
Brookhaven National Laboratory
Probing the Unitarity Triangle with Rare K Decays
Seminars in 2000
Tuesday Jan. 18 2000 1:30
Scott Oser
University of Chicago
Closing the Gap: First Results from STACEE
Tuesday Feb. 15 2000 1:30
Glenn Horton-Smith
Tohoku University, Japan
Introduction to KamLAND, the 1-kT Liquid scintillator
Anti-Neutrino Detector at Kamioka
Tuesday Feb. 22 2000 1:30
Artur Barczyk
ETH-Zurich
Measurement of W Boson Properties with the L3 experiment at LEP
Monday Feb. 28 2000 1:00
Kael Hanson
University of Michigan
A Measurement of the Neutrino-Induced Muon Flux at the MACRO Detector
Tuesday Feb. 29 2000 1:30
Klaus Rabbertz
Aachen
Event Shapes and Power Corrections in ep DIS
Monday Apr. 10 2000 3:30
Jens Erler
University of Pennsylvania
Is there a hint for a new Z boson in the precision data?
Friday Apr. 28 2000 1:00
Sherri Towers
Carleton Institute for Physics, Ottawa, Canada
Really Strange Tau Physics
Tuesday Nov. 7 2000 at 1:30
Hal Evans
Columbia University
B-Physics at Dzero (it’s not just production any more)
Tuesday Nov. 14 2000 at 1:30
Paul Langacker
Penn
Electroweak Physics at LEP
Tuesday Nov. 21 2000 at 1:30
Larry Gladney
Penn
Recent Results from BABAR
Monday Dec. 4 2000 at 12:45
Kazuo Abe
KEK
Recent Results from BELLE
Tuesday Dec. 12 2000 at 1:30
Frank Paige
Brookhaven National Laboratory
Physics at a 500 GeV Linear Collider
Monday Dec. 18 2000 at 12:45
Chris Tully
Princeton University
Status of LEP-wide Higgs Searches
Seminars in 1999
Feb. 2 1999
Josh Klein
University of Pennsylvania
Sudbury Neutrino Observatory: Current Status
Feb. 5 1999 AT 1:00
Mary Anne Cummings
Northern Illinois University
Top Quark Production in the All-Jet Channel at D0 and/or Radiocoherence and Neutrino Physics
Feb. 8 1999 AT 1:00
Jean Duboscq
Ohio State University
The Tau Neutrino Mass Limit at CLEO and Elsewhere
Mar. 2 1999 at 1:30
Amit Lath
Rutgers University
Recent Results on Rare Processes and New Physics from KTeV
Friday, March 5 1999 at 1:30
Aaron Dominquez
CERN
Higgs searches at L3 using the 189 GeV data
Mar. 16 1999 at 1:30
Brad Cox
University of Virginia
New Results from KTeV on Time Reversal Violation
Mar. 30 1999 at 1:30
Ikaros Bigi
University of Indiana
The Brown Muck of Beauty — The Beauty of the Brown Muck
Thursday, Apr. 22 1999 1:00 3N6 DRL
John Beacom
Caltech
Neutrinos from the Next Galactic Supernova
Monday Sep. 13 1999 AT 4:00
Kate Frame
Michigan State University
A New Jet Finding Algorithm For Hadron Colliders
MONDAY Oct. 11 1999 at 1:30 3N6 DRL
Jim Hill
SUNY/Stony Brook
First Data from the K2K Experiment
Tuesday Oct. 19 1999 at 1:30
Yongsheng Gao
Harvard University
Observation of B –> Pseudo-scalar and vector meson Decays at CLEO
Tuesday Nov. 2 1999 at 1:30
Wasiq Bokhari
University of Pennsylvania
Status of Higgs Boson Searches at the Tevatron
Tuesday Nov. 9 1999 at 1:30
Joao Guimaraes da Costa
University of Michigan
b’ Quark: The Next Generation
Thursday Nov. 11 1999 at 1:00 in 2N36 DRL
George Hou
National Taiwan University
Constraints on Gamma in the Unitarity Triangle
Seminars in 1998
Jan 27 1998
George Smith
Yacht Apogee (Israel)
The History and Current Status of the CCD
Feb 9 1998
Rene Ong
University of Chicago
The Solar Tower Atmospheric Cherenkov Effect Experiment
Feb 10 1998
Jesse Stone
Princeton
K -> pi nu nu
Feb 17 1998
Mark Oreglia
University of Chicago
Results from the 183 GeV Running of OPAL
Feb 18 1998, 2pm
Chris Mindas
Princeton
K+ -> mu+ pi0 nu decays
Mar 31 1998 2:00 pm
Ed Kearns
Boston University
Atmospheric Neutrino Results from SuperKamiokande
Apr 7 1998
Jim Beatty
Pennsylvania State University
Status of the Pierre Auger Project
Apr 14 1998
Tom Devlin
Rutgers University
Observation of the B_c Meson
Apr 28 1998
Kirk McDonald
Princeton University
The Physics of a Muon Collider
Oct 27 1998
George W.S. Hou
Brookhaven National Lab./National Taiwan University
West Indies, or New Continent–CP Violation at B Factories
(A phenomenological talk prepared for experimentalists.)
November 3 1998
Kate Scholberg
Boston University
The International Supernova Neutrino Alert Network
December 1 1998
Richard Steinberg
Drexel University
The CHOOZ Experiment
Seminars in 1997
Oct 6 1997
Eric Prebys
Princeton University
SLAC E-144:
Results from Sparking the Vacuum
Oct 13 1997
Tim Bolton
Kansas State University
Electroweak Physics with the NuTeV Detector at Fermilab
Nov 3 1997
Samim Erhan
UCLA
B Physics in the 21st Century
Nov 17 1997
David Stuart
Fermilab
The Search for New Phenomena at CDF
Nov 24 1997
Steven Ritz
Columbia University
The GLAST Experiment
Dec 1 1997
Andrew Bazarko
Princeton University
K –> pi nu nu
Dec 8 1997
Young-Kee Kim
UC-Berkeley
Precision Tests of the Electroweak Interaction from Hadron Colliders