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Wednesday, November 30, 2011
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Chuanzhe Lin
[Host: Bob Hirosky]
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3:30 PM, Room 204
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University of Virginia |
| Physics Building |
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“Measurement of the Triple Differential Cross Section of Photon plus Jet in pp Collisions at 7 TeV” |
ABSTRACT:
| Hawking showed many years ago that pair production near black holes would violate quantum mechanics. But while many relativists were convinced about information loss, string theorists hoped that small subleading corrections to Hawking's computation would invalidate his result. Recently an inequality was derived that shows that such small corrections do not in fact change Hawing's argument. What happens instead, however, is that the structure of the black hole gets altered at the horizon due to the emergence of a new length scale for quantum effects, creating states called fuzzballs. In this talk I will give an overview of these developments, which taken together give us a resolution of the information paradox. |
ABSTRACT:
| The radio detection technique for High Energy Cosmic Ray Shower detection has been investigated in this collaborative work. High Energy Cosmic Ray Showers produce disk-like ionization front which moves with relativistic speed in our atmosphere. We study the reflection of radio waves such as the ones from commercial radio and TV stations from the relativistic moving front. The reflected wave experiences a high blue-shift in frequency due to relativistic Doppler effect. The feasibility study of detection of showers via this method and the benefits will be presented. |
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Wednesday, October 26, 2011
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Reserved for Special Colloquium
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3:30 PM, Room 204
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| Physics Building |
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ABSTRACT:
| A measurement of the differential cross section for the inclusive production of isolated prompt photons in proton-proton collisions at a centre-of-mass energy of 7 TeV is presented. The data sample corresponds to an integrated luminosity of 36 pb-1 recorded by the CMS detector at the LHC. The measurement covers the pseudorapidity range
|η| < 2.5 and the transverse energy range 25 < ET < 400 GeV, corresponding to the kinematic region 0.007 < xT < 0.114. Photon candidates are identified with two complementary methods, one based on photon conversions in the silicon tracker and the other on isolated energy deposits in the electromagnetic calorimeter. The measured cross section is presented as a function of ET in four pseudorapidity regions. The next-to-leading-order perturbative QCD calculations are
consistent with the measured cross section. |
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Wednesday, May 4, 2011
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Kunal Kathuria
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3:30 PM, Room 204
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University of Virginia |
| Physics Building |
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“Spin Crisis and Orbital Angular Momentum> in Hadrons” |
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Wednesday, April 27, 2011
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Huong Nguyen
[Host: Bob Hirosky]
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3:30 PM, Room 204
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University of Virginia |
| Physics Building |
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“Search for the SM Higgs Boson in Lepton plus Jets Final States” |
ABSTRACT:
| The Upsilon resonances provide a clear signal for early analysis with LHC data. As such it is ideal as a testing and calibration tool. Despite its unambiguous signal and comparatively large cross section Upsilon production at hadron colliders is not entirely understood. I will present the first Upsilon cross section measurement from CMS, and look at its place with other hadron collider experimental results and with the latest theoretical predictions.
In the future, the LHC environment will place increasing challenges on the detector systems there. One promising technology utilizes pixelated APD's operating in Geiger mode to measure light intensity. Such devices have many advantages and some drawbacks. I will look at the basic application of this family of sensors in hadronic calorimetry and explore more specific applications being developed and deployed by the CMS hadronic calorimeter community.
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Joint HEP/Nuclear Seminar
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Tuesday, April 12, 2011
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Guy Moore
[Host: Peter Arnold]
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3:30 PM, Room 204
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McGill |
| Physics Building |
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“TBA” |
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Wednesday, April 6, 2011
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Yuri Oksuzian
[Host: Craig Group]
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3:30 PM, Room 204
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UVa |
| Physics Building |
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“A search for resonant production of Top quarks pairs at CDF” |
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Wednesday, March 2, 2011
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Daniel Stolarski
[Host: Chris Neu]
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3:30 PM, Room 204
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University of Maryland |
| Physics Building |
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“Little Higgs and Superlatives” |
ABSTRACT:
| Little Higgs models revive the old idea of the Higgs being a pseudo-Goldstone boson. These models are motivated by the little hierarchy problem and present many interesting signatures for the LHC.
In this talk I will review the Little Higgs mechanism and describe some of the models in the literature. I will then describe some of the problems with existing models, and conclude by discussing a new model that I worked on with Jesse Thaler and Martin Schmaltz
(arXiv:1006.1356 [hep-ph]).
|
ABSTRACT:
| The effective action encoding elastic transport properties of topological insulators involves effective (non-dynamical) 'gravitational' variables. In the case of 2+1-dimensional time-reversal breaking topological insulators, the leading term in the action is a 'Chern-Simons' action involving the torsion of the connection. The coefficient of this term is the dissipationless Hall viscosity, a direct analogue of the Hall conductivity. In this talk, we review the calculation of the Hall viscosity in a simple model, and discuss its interesting renormalization properties. |
ABSTRACT:
| We give a simple recipe for computing dissipation and fluctuations (commutator and anti-commutator correlation functions) for non-equilibrium black hole geometries. The recipe formulates Hawking radiation as an initial value problem, and is suitable for numerical work. We show how to package the fluctuation and dissipation near the event horizon into correlators on the stretched horizon. These horizon correlators determine the bulk and boundary field theory correlation functions. In addition, the horizon correlators are the components of a horizon effective action which provides a quantum generalization of the membrane paradigm. In equilibrium, the analysis reproduces previous results on the Brownian motion of a heavy quark. Out of equilibrium, Wigner transforms of commutator and anti-commutator correlation functions obey a fluctuation-dissipation relation at high frequency. |
ABSTRACT:
| The solution to the fermion sign problem forces one to sum over a class of fermion configurations before a Monte Carlo algorithm can be designed. Conventionally this makes it necessary to compute the determinant of an N x N matrix at every step where N is large. Thus, it is important to optimize the value of N. Conventional approaches based on the Hubbard Stratanovich transformation set N = Volume or N = number of particles. We suggest a new approach in which N is optimized by the nature of the interactions. Effectively, the coupling is used to isolate a set of fermion degrees of freedom that interfere with each other and thus create a fermion bag. Thus, N is determined by the size of this bag. Using a simple example of the massless Lattice Thirring model we show that at both weak and strong couplings the bag size can be small. Thus, we can design algorithms that are far more efficient than the conventional algorithms in these regions of the coupling. |
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Wednesday, January 26, 2011
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Abhijit Majumder
[Host: Peter Arnold]
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3:30 PM, Room 204
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Ohio State |
| Physics Building |
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“Setting up jet-modification as a probe of QCD media at HERA, RHIC and LHC” |
ABSTRACT:
| The modification of hard jets in dense extended media such as large nuclei or a deconfined quark gluon plasma will be described in a factorized formalism where the hard partons couple weakly with the medium, where the medium may itself be strongly or weakly coupled. The effect of the medium will be parametrized in a handful of transport coefficients which are obtained as the in-medium expectation of well defined operator products. We will attempt to describe the attenuation of the yield of leading hadrons in DIS at HERA and heavy-ion collisions at RHIC as well as the centrality, azimuthal anisotropy and flavor dependence (at RHIC) in a single formalism. Also preliminary results from a new Monte-Carlo event generator based on this formalism will be presented and compared with the new LHC measurements of dijet asymmetry. |
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Wednesday, January 19, 2011
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Kristian Hahn
[Host: Chris Neu]
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3:30 PM, Room 204
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MIT |
| Physics Building |
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“W/Z Physics at CMS” |
ABSTRACT:
| In this talk I discuss recent measurements of the Z ---> l+l- and W
---> lv inclusive cross-sections performed by the CMS collaboration.
W and Z gauge boson production has been among the first physics
studied
at the LHC and the CMS results are an important test of Standard
Model predictions at the unprecedented pp center-of-mass collision
energy of 7 TeV. Events are selected for the analysis by requiring
the presence of energetic, isolated electrons or muons. The presence
of an energetic neutrino is demonstrated using the distribution of
missing transverse energy. I describe the criteria used for lepton
identification, as well as the data-driven techniques employed in the
estimation of efficiencies, in the tuning of Monte Carlo simulation
and in the determination of the most important background
contributions. I discuss the methods used to evaluate experimental
uncertainties and present relevant kinematic distributions and the
extracted cross-sections.
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Wednesday, November 17, 2010
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Thomas Cohen
[Host: Peter Arnold]
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3:30 PM, Room 204
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University of Maryland |
| Physics Building |
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“The Large Limits of QCD” |
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Wednesday, October 20, 2010
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Djordje Minic
[Host: Diana Vaman]
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3:30 PM, Room 204
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Virginia Tech |
| Physics Building |
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“The Jarzynski Identity and the AdS/CFT Duality” |
ABSTRACT:
| I will discuss a remarkable analogy between the Jarzynski identity
from non-equilibrium statistical physics and the AdS/CFT duality. I will apply
the logic that leads to the Jarzynski identity to renormalization group (RG)
flows of quantum field theories and then argue for the natural connection with
the AdS/CFT duality formula. This application can be in principle checked in
Monte Carlo simulations of RG flows. Given the existing generalizations of the
Jarzynski identity in non-equilibrium statistical physics, and the analogy
between the Jarzynski identity and the AdS/CFT duality, we are led to suggest
natural but novel generalizations of the AdS/CFT dictionary. The talk is based
on arXiv:1007.3970 (with Michel
Pleimling).
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Wednesday, October 13, 2010
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Reserved for Nuclear Seminar
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3:30 PM, Room 204
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| Physics Building |
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Wednesday, May 5, 2010
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Chris Hays
[Host: Chris Neu]
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3:30 PM, Room 204
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Oxford University |
| Physics Building |
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“Low-Mass Dimuons at CDF: Dark Forces, Higgs Bosons, and Data Anomalies” |
ABSTRACT:
| Various studies of collider and cosmological data have found multilepton sources that are not well described by the usual models. These studies have motivated a theory of a new force at the O(1 GeV) energy scale that interacts with standard-model particles only through a high-mass intermediary. This new 'dark' force could produce multiple leptons at small angles, dubbed 'lepton jets,' at hadron colliders.
I describe a general CDF search for high-momentum muon pairs with sensitivity to any new low-mass resonance. I also briefly discuss the possibility that the Higgs boson is a source of high-momentum dimuons, with a mass lower than the usual LEP bounds and more consistent with supersymmetry and the global electroweak fits.
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Wednesday, April 21, 2010
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Rachel Yohay
[Host: Brad Cox]
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3:30 PM, Room 204
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University of Virginia |
| Physics Building |
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“Searching for Gauge-Mediated Supersymmetry Breaking in the Large Hadron Collider's First Events” |
ABSTRACT:
| With the LHC recently having achieved collisions at a world-record center of mass energy of 7 TeV, particle physics is moving into a new era. The collision environment at the LHC is determined by the accelerator but also by the structure of the proton. The LHC will probe smaller momentum fractions with higher momentum transfers than any previous collider. I will discuss some of the planned techniques to study and constrain the proton structure using electroweak bosons as probes in LHC collisions. These measurements are a key component to our understanding of the backgrounds to possible new physics signatures and also have relevance for constraining the explanations for any new observation. |
Joint HEP/Nuclear Seminar
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Monday, April 12, 2010
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Guy Moore
[Host: Peter Arnold]
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3:30 PM, Room 204
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McGill |
| Physics Building |
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“TBA” |
ABSTRACT:
| Standard Model theory does not allow Lepton Flavor Violating (LFV)
decays, however other extensions like SUSY, Pati-Salam Lepto-Quark
(LQ) and Extra-Dimension(ED) models allow the LFV decays. In these
models, the assumption of a local gauge symmetry between quarks and
leptons at the lepton-flavor violation tree-level couplings lead to the
prediction of a new force of nature which mediates transitions between
quarks and leptons, hence LFV searches are important tool to search for
New Physics beyond SM. I will discuss about the progress I have made
in the search for the mentioned decay using data collected by D0
detector at Tevatron. |
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Wednesday, March 24, 2010
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Justin Keung
[Host: Chris Neu]
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3:30 PM, Room 204
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University of Pennsylvania |
| Physics Building |
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“Search for WZ in the l nu b bbar Final State at CDF” |
ABSTRACT:
| An important search channel for the Higgs boson is associated WH production with subsequent decays of W -l nu and H -b bbar. The identification of b-quark jets is an important component in this search. We discuss the commissioning of a new artificial neural network b-quark jet identification algorithm. The resulting final state is shared with standard model WZ production which necessarily must be well-understood. We discuss an important cross-check of the WH search which is to apply the same techniques to measuring the WZ contribution to our event candidate sample. |
Joint HEP / CM Seminar
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Wednesday, January 20, 2010
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Eddy Barnes
[Host: Diana Vaman]
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3:30 PM, Room 204
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University of Virginia |
| Physics Building |
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“Introduction to AdS/CFT and its applications” |
ABSTRACT:
| The anti-de-Sitter space/conformal field theory (AdS/CFT) correspondence is a powerful tool in the study of conformal field theories, which are ubiquitous in High Energy and in the study of phase transitions in Condensed Matter (CM) and cold atomic systems. AdS/CFT is a conjectured duality that maps a CFT without gravity to a string theory on a curved space. In regimes where the CFT is most difficult to solve, the string theory tends to be simple, effectively reducing to Einstein’s gravity theory. I will begin with an extensive introduction to the basic features of AdS/CFT. I will describe some of my own research using it in the context of scattering amplitudes and time-dependent thermal processes. I will also discuss some of the exciting new applications to CM and cold atomic systems and conclude with possible future directions along these lines.
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ABSTRACT:
| I will review and present new results regarding the phenomenology of the two (presumably) lightest scalars in the context of warped extra dimensions: the Higgs and the radion. This last one, could be the lightest "new physics" state to be discovered at the LHC in this type of models. Its phenomenology is very similar to the Standard Model
(SM) Higgs. When SM fields are allowed to live in the bulk of the extra dimension, new interesting effects appear in the scalar sector of the model. In particular, both the Higgs and the radion can now typically mediate Flavor Changing Neutral Currents at tree level. These will impose bounds on the flavor structure of the model, but also allow for interesting probes in current and future collider experiments.
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ABSTRACT:
| The Standard Model describes the unification of electromagnetic and weak interactions. It was thoroughly tested over past thirty years, and represents one of the major successes of modern physics. This theory predicted the existence and the masses of the weak bosons. The last remaining piece of the puzzle is the Higgs boson whose existence is crucial for our understanding of the origin of particle masses.
Direct searches at LEP put a lower limit on the Higgs boson mass, and together with precision measurement constrained it to <~200 GeV. The D0 and CDF experiments at the Tevatron recently excluded a new interval in the Higgs mass. In this time when we are entering LHC era, we are coming closer to the discovery or exclusion of the SM Higgs boson. I will discuss current searches for the SM Higgs boson with the D0 experiment at Tevatron, highlighting the most important techniques. I will also draw a parallel with future searches at LHC, showing what we can learn from Tevatron experience.
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ABSTRACT:
| Over the last years, gauge/string duality has been extended to include gauge theories with an arbitrary number of flavors. We study the flavoring procedure in the light of calibrated geometry and discuss the special case of a type IIA dual of N=1 super Yang-Mills with flavors.
Relating our results to the standard type IIA/M-theory duality, we find that the usual oxidation formulas cannot accommodate for the additional flavor branes. We address and solve this issue by considering M-theory with torsion, which allows us to construct source-modified equations of motion for eleven-dimensional supergravity.
|
Joint HEP/Nuclear Seminar
ABSTRACT:
| The perturbative expansion of the pressure of QCD is known to order g^6 log(g), however, the resulting series is poorly convergent at phenomenologically relevant temperatures/couplings. I will discuss a method for improving the convergence of the successive approximations to the QCD pressure in a systematic manner which exactly reproduces the perturbative series in the weak-coupling limit. The method relies on folding in information about the correct high-temperature degrees of freedom via the hard-thermal-loop (HTL) resummation scheme. In order to give some background I will also discuss the poor convergence of quantum mechanics for the ground state of an anharmonic oscillator and present results for the three loop HTL-improved pressure of QED. Finally, I will present new results of an HTL-improved calculation of QCD thermodynamics to three-loops and critically discuss how this compares to available lattice data. |
ABSTRACT:
| We present the concept of a Digital Hadron Calorimeter (DHCAL) for use in a detector optimized for the application of Particle Flow Algorithms to the measurement of jet energies.
Resistive Plate Chambers
(RPCs) with 1 x 1 cm^2 readout pads are used as active elements. The front-end electronic readout is integrated on the pad-boards of the chambers and applies a single threshold (1-bit) to the signal charges, hence the designation of digital readout.
We report on detailed measurements with a small scale prototype in the Fermilab test beam using muons, positrons, pions, and protons and in the laboratory using cosmic rays.
The results validate the concept and serve as basis for the design of a large prototype calorimeter. An update on the ongoing construction of the latter will be given.
|
ABSTRACT:
| Many precision tests of the Standard Model require input from Lattice QCD (LQCD). Of particular importance are the semileptonic form factors used to extract Vub in semileptonic B decays. Similarities between the D and B sector make charm semileptonic decays an excellent testing ground for the increasingly precise predictions of LQCD. CLEO-c has recently used its entire data sample to produce a set of measurements involving the decays D0 → pi e nu, D0 → K e nu, D+ → pi0 e nu and D+ → K0 e nu. These results, which include the worlds most precise branching fraction and D -> pi form factor measurements, will be discussed. |
ABSTRACT:
| I will present the results of the search for the electron antineutrinos from the Sun with Kamioka Liquid scintillator Anti-Neutrino Detector (KamLAND). There is no known direct production of the electron antineutrinos in the Sun. However, in the some theoretical models with the large neutrino magnetic moment antineutrinos from the Sun can be produced e.g. via Spin Flavor Precession mechanism (SFP). Search for solar antineutrinos potentially can provide new information about fundamental properties of neutrinos. The most sensitive one-kiloton antineutrino detector KamLAND gives the possibility to search for such antineutrinos. The analysis described in this dissertation is based on 1425.9 days of data collection in KamLAND. The search for the electron antineutrinos have been made within 8.8-16.3MeV antineutrino energy range, that is above energies of reactor antineutrinos and where properties of the solar B8 neutrinos are well studied. Based on the number of observed candidates and estimated background rates the upper limit on the electron antineutrino flux and probability of conversion electron neutrinos produced in the Sun to electron antineutrinos was set. The same limit can be used on the diffuse Supernovae neutrino flux. The estimated background rates during this study can make significant impact on the design of the future neutrino scintillator detectors. |
ABSTRACT:
| The ATLAS Pixel Detector is the innermost detector of the ATLAS experiment at the Large Hadron Collider at CERN. With approximately 80 million readout channels, the ATLAS silicon pixel detector is high-acceptance, high-resolution, low-noise tracking device providing the desired refinement in charged track pattern recognition capability in order to meet the stringent track reconstruction requirements of ATLAS, largely defining its ability to effectively resolve primary and secondary vertices and perform efficinet flavor tagging essential for discovery of new physics.
Being the last sub-system installed in ATLAS by the end of June 2007, Pixel Detector was successfully connected, commissioned, and tested in situ while meeting an extremely tight operations schedule, and is ready to take data upon the projected turn-on of the LHC at the end of 2009.
UT Dallas group has successfully deployed and commissioned the environmental controls for the opto-links, crucial for stable operation of the readout electronics of the pixel detector. Since fall 2008, Pixel Detector was included in the combined ATLAS detector operation, collecting physics data with cosmic muons. Details from the Pixel Detector installation and commissioning, as well as the details on major calibration procedures and the results obtained with collected cosmic data, are presented along with the current ATLAS detector status summary.
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Thursday, September 17, 2009
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Ralf Ehrlich
[Host: Craig Dukes]
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4:00 PM, Room 313
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University of Maryland |
| Physics Building |
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“The Search for Neutralino Dark Matter with the AMANDA Neutrino Telescope” |
ABSTRACT:
| There is convincing indirect evidence based on cosmological data that approximately one quarter of the universe is made of dark matter. However, to this date there is no direct detection of the dark matter and its nature is unknown. Many theories suggest that dark matter is made of supersymmetric particles, and the most promising candidate out of the supersymmetric particles is the lightest neutralino. These neutralinos can get gravitationally trapped in the Earth, where they eventually annihilate. The annihilation products decay and a fraction of the decay products are muon-neutrinos, which can be detected with the AMANDA/IceCube neutrino telescope in the ice at the South Pole.
Neutrinos cannot be detected directly. However, there is a small possibility that they interact with the nuclei of the ice via a charged current interaction and "create" charged leptons. These charged leptons continue to travel in almost the same direction as the neutrinos. As long as their speed is higher than the speed of light of the ice, they emit Cherenkov radiation which can be captured by photomultipliers installed inside the ice. A hypothetical muon-neutrino flux from neutralino annihilations inside Earth should show up as an excess over the expected muon-neutrino flux from atmospheric neutrinos produced in the northern hemisphere. No significant excess has been observed, yielding an upper limit on the neutrino flux that could have come from neutralino annihilation.
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Wednesday, August 26, 2009
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Nikos Varelas
[Host: Bob Hirosky]
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3:30 PM, Room 204
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Univ. of Illinois, Chicago |
| Physics Building |
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“QCD Physics at CMS” |
ABSTRACT:
| The Large Hadron Collider (LHC) at CERN will soon be at the frontier of experimental High Energy Physics. It is expected to start colliding proton-proton beams later this year at an initial center-of-mass energy of 10 TeV. It will be a unique tool for fundamental physics research with an unprecedented physics potential,probing distances down to 10 (-20) m. In this talk, I will discuss the potential of the Compact Muon Solenoid Detector (CMS), one of four experiments at the LHC, to study the fundamental theory of the strong interactions – Quantum Chromodynamics (QCD) – using a variety of final states and observables with the first experimental data. |
Physics Day Show
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Wednesday, April 22, 2009
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O. Pfister,C. Sackett, K. Williams, S. Wolf
[Host: Mike Timmins]
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7:00 PM, Room 203
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University of Virginia |
| Physics Building |
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“Lasers” |
ABSTRACT:
| The 15th annual physics demonstration sow will be held Wednesday evening, April 22nd, 2009 in room 203 of the physics building at the University of Virginia to celebrate National Physics Day. This highly anticipated event is a special family oriented physics demonstration show for the general public. The show this year will be at 7:00 p.m. in the physics building on McCormick Road. Parking is available in the parking garage on Emmett Street, or after 5:00 p.m. in the football stadium parking lots.
Physics professors Olivier Pfister, Cass Sackett, Keith Williams, Stuart Wolf and Mike Timmins will delight the crowd with strange and mystifying events. When the laser was first invented in 1958, it was immediately considered a “solution waiting for a problem”. Well, that was a long time ago and we have since found many problems that the laser is a perfect solution for. In fact, lasers are ubiquitous in everyday modern electronics from simple pointing instruments to cd/dvd players. However, lasers are even more useful to researchers and after this show, you will begin understand why. The demonstrations are designed to intrigue and excite both young and old from novice to expert. Bring your family and friends, but come on time as the room fills up quickly. For more information about this free public event, call 924-3781.
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Wednesday, April 8, 2009
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Reserved for Atomic Seminar
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3:30 PM, Room 204
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|
|
| Physics Building |
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ABSTRACT:
| When the LHC starts its operation, it will produce large number of charm quarks even in low luminosity runs during the first few years of running. With precision tracking and nearly complete muon coverage, the CMS detector is well suited to the study of quarkonium through its di-muon decays. We report the methods and plans for measuring the differential p T J/ ψ → μ+μ− production cross section, using data to be collected in the first LHC run by the CMS detector. |
ABSTRACT:
| A general introduction is presented into the field of B-meson physics, the BaBar experiment, and the motivation for the branching ratio measurement of the B-meson decay Bd->D*a0. The branching ratio of this decay is sensitive to non-factorizing terms of QCD factorization, which is generally used to calculate the amplitudes of meson decays.
Second, this decay can be extremely sensitive to the CKM-angle gamma, the least accurately known angle of the CKM Unitarity Triangle. An experimental challenge of this measurement is posed by the low expected branching ratio of the decay (order 10-6), in combination with the high background levels from related B-meson decays. The analysis uses more than 30 selection variables and an unbinned likelihood fit performed simultaneously in three observables. The optimization procedure of the data selection and the setup of the likelihood fit are presented in the talk. The both promising and remarkable results of the branching ratio measurement are discussed.
|
ABSTRACT:
| Photons produced in association with heavy flavor quarks provide a unique window into both the sea quark content of the proton and the splitting of gluons into heavy flavor quark pairs. A new combination of experimental techniques at the Tevatron has provided the basis for the first measurements of the differential photon plus heavy flavor jet production cross sections at 1.96 TeV. Results of these measurements and comparisons to next-to-leading order theoretical predictions will be presented. |
ABSTRACT:
| I present results on the measurement of the inclusive direct photon production cross section in proton-antiproton collisions at #sqrt(s) = 1.96 TeV, using data collected with the upgraded Collider Detector at Fermilab in Run II, and corresponding to an integrated luminosity of 2.5 fb-1. Measurements are performed as a function of the photon transverse momentum for photons with pT > 30 GeV and |eta| < 1.0. Photons are required to be isolated in the calorimeter (isolation ET < 2 GeV). We use the calorimeter isolation distribution to estimate the contamination from jets faking isolated photons. The measured cross section is corrected back to the hadron level and compared to NLO pQCD predictions. The NLO pQCD predictions include non-perturbative corrections. We find good agreement between data and the theoretical predictions.
|
ABSTRACT:
| I will present a recent ZEUS measurement of beauty photoproduction in dijet events at HERA. In the analysis, b-quark events are identified in the semi-leptonic decay mode using a technique which exploits the long lifetime of the B hadron. This is the first measurement of its kind at ZEUS as it uses the Micro-Vertex Detector (MVD), an upgrade made to ZEUS for the HERA II running period. I will describe the analysis method involved in the measurement and then present the results which include beauty production cross sections as well as dijet correlations.
The results are compared to QCD predictions and previous measurements.
|
ABSTRACT:
| Great improvements have been made since the evidence of single top quark production at DZero in 2006 with 1 fb-1 of data. Here I present the signal and background modeling, event selection, multivariate techniques and statistical tools for the measurement of the cross section using 2.3 fb-1 of data. |
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Wednesday, February 4, 2009
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Reserved for Condensed Matter Seminar
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3:30 PM, Room 204
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|
|
| Physics Building |
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|
ABSTRACT:
| Extensive tests have been carried out with the ATLAS liquid argon(
LAr) calorimeter system. This talk presents the highlights of the LAr commissioning activities. Supersymmetry searches at ATLAS are summarized, with a focus on the search for a light supersymmetric top squark (stop). A light stop is motivated by theories of electroweak baryogenesis in the Minimal Supersymmetric Standard Model (MSSM). An MSSM benchmark point, LST1, with a stop mass of 150 GeV is investigated for potential discovery with the ATLAS detector.
|
ABSTRACT:
| The Higgs boson is the last missing particle within the Standard Model of particle physics and the largest focus of research efforts at the Fermilab Tevatron collider. The combination of the searches for the Standard Model Higgs boson at a center-of-mass energy of sqrt(s)=1.96 TeV using up to 4 fb^-1 of data collected with the D0 detector will be presented. The major contributing processes include associated production (WH->l+nu+b+b, ZH->nu+nu+b+b,
ZH->l+l+b+b, and WH->WWW^(*)) and gluon fusion (gg->H->WW^(*)). The
significant improvements across the full mass range resulting from the larger data sets, improved analyses and inclusion of additional channels are discussed. The prospects for expanding the Higgs sensitivity region though the end of Tevatron operation will also be discussed.
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Thursday, November 13, 2008
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Pelin Kurt
[Host: Chris Neu]
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3:30 PM, Room 123
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|
Kurkova University |
| HEP Building |
|
“Jet Shapes Studies at CMS” |
ABSTRACT:
| The CMS (Compact Muon Solenoid) detector will observe high transverse momentum jets produced in the final state of proton-proton collisions at the center of mass energy of 14 TeV. These data will allow us to measure jet shapes, defined as the fractional transverse momentum distribution as a function of the distance from the jet axis. Since jet shapes are sensitive to parton showering processes they provide a good test of Monte Carlo event simulation programs. A potential method was investigated to measure jet shapes in CMS using reconstructed calorimeter energies where the statistics of all distributions correspond to a CMS data set with 10 pb -1 of integrated luminosity. We compare the predictions of the Monte Carlo generators PYTHIA and HERWIG++. |
ABSTRACT:
| I will present the latest results from CDF in the study of top
quark production. A little over a decade after the discovery of the
Top quark the Tevatron has now produced over 10 times the
statistics of the first experiment . Because of this, we are finally now able
to precisely test the top quarks place in the Standard Model. In
the same amount of time it took to collect this data, measurement
techniques have advanced at a similar pace. I will discuss two new
state-of-the-art measurements with the latest data of the top quark
cross section. These new measurements are the first to reach the
precision of the theoretical cross-section, and have managed to
resolve a long-standing discrepency between previous measurements.
In addtion, a new measurement, the forward backward asymmetry is
discussed. The 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, October 28, 2008
|
|
Jason Slaunwhite
[Host: Chris Neu]
|
|
3:30 PM, Room 204
|
|
Ohio State University |
| Physics Building |
|
“Search for Higgs Bosons Produced in Association with W Bosons at CDF” |
ABSTRACT:
| The Higgs boson is a result of electroweak symmetry breaking in the Standard Model. The Higgs is experimentally unobserved, despite the Standard Model's prediction of it's existence. We present a search for a Standard Model Higgs bosons produced in association with a W bosons in proton anti-proton collisions recorded at CDF. Our search uses a dataset corresponding to an integrated luminosity of 2.7/fb. Our candidate events have one high-momentum muon or electron, missing ET, and a Higgs that decays to a pair of b-quarks jets. We extended the reach of the search by including events without a triggered lepton. We employ several b-quark identification algorithms to enhance the purity of Higgs events. An Artificial Neural Network improves our discrimination of Higgs signal kinematics from background processes such as top pair production and W+jets. We perform a likelihood fit of the neural network output distribution and set 95% confidence level upper limit on the associated production cross section times branching ratio as a function of Higgs mass.
|
|
Monday, October 27, 2008
|
|
Amihay Hanany
[Host: Diana Vaman]
|
|
3:30 PM, Room 313
|
|
Imperial College |
| Physics Building |
|
“Brane Tilings, CS Theories, and M2 Branes” |
ABSTRACT:
| The determination of the element |Vub| of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix plays a central role in the search for flavour and CP violation beyond the Standard Model. In this seminar, we will present measurements of partial branching fractions for inclusive charmless semileptonic decays, B -> Xu l nu, in limited regions of phase space and the corresponding values of |Vub|, as extracted using several theoretical calculations. The invariant mass of the hadronic system, Mx, the squared invariant mass of the lepton pair, q2, and the variable P+ = Ex-|Px|, or one of their combinations, in the process B -> Xu l nu are used as discriminating variables to suppress semileptonic decays with charm. Partial branching fractions are measured as functions of the cuts on the above variables. Different theoretical models are used to compute acceptances and related uncertainties, thereby allowing to extract |Vub|.
> These studies are performed on a sample of 383 million BB events collected at the Υ(4S) resonance, with the BaBar detector at the PEP-II e+e- storage rings
|
|
Wednesday, October 15, 2008
|
|
Viktor Veszpremi
[Host: Christopher Neu]
|
|
3:30 PM, Room 120
|
|
Cornell University |
| Physics Building |
|
“Search for new physics with b-quark jets” |
ABSTRACT:
| The new energy regime and higher data-taking rate of the LHC will soon extend the possibilities of searches for yet undiscovered particles and phenomena. Final states produced via b-quark decays are often created by physics beyond the standard model; they are also favored in light standard model Higgs boson processes. High-pt B-tagging, therefore, has been and continues to be one of the most important tools in searches both at the Tevatron and at the LHC. In the first half of my presentation, I will introduce the CMS pixel detector, a component of the CMS tracking system that is vital for B-tagging, and talk about the on-going calibration efforts in its commissioning. In the second half of my presentation, I will demonstrate the use of B-tagging in physics analyses through an example of a low-mass standard model Higgs boson search perfomed in the CDF experiment at the Tevatron. |
|
Wednesday, October 8, 2008
|
|
Luke Corwin
[Host: Chris Neu]
|
|
3:30 PM, Room 204
|
|
Ohio State University |
| Physics Building |
|
“Measuring Fully Leptonic Charged B Decays in the Recoil of Semileptonic B Decays at BaBar” |
ABSTRACT:
| After a brief review of the theoretical predictions and
experimental difficulties presented by fully leptonic charged B decays, I will review the latest search for charged B decays into lepton neutrino pairs, where the lepton can be an electron, muon, or tau, in the recoil of a semileptonically decaying charged B. This search uses the full data set collected at the BaBar experiment.
|
|
Wednesday, September 17, 2008
|
|
Kate Scholberg
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
Duke University |
| Physics Building |
|
“The CLEAR Experiment: Measuring Neutrino-Nucleus Coherent Scattering at the Spallation Neutron Source” |
ABSTRACT:
| A low-threshold neutrino scattering experiment at a high intensity stopped-pion neutrino source has the potential to measure coherent neutral current neutrino-nucleus elastic scattering. This process has never been observed and presents opportunities for new tests of the Standard Model. A promising prospect for the measurement of this process is a proposed noble-liquid-based experiment called CLEAR (Coherent Low Energy A(Nuclear) Recoils), at the Spallation Neutron Source. This talk will describe the CLEAR experiment and its physics reach. |
ABSTRACT:
| One of the greatest theoretical triumphs in the history of physics has
been the unification of the electromagnetic and weak forces. This
theory successfully predicted the masses of the W and Z bosons which
were later measured at CERN, and involves a mechanism that provides
all particles with mass. This mechanism also predicts the existence
of another observable particle, known as the Higgs boson. Experiments
at the LEP collider have placed a lower bound on its mass of 114 Gev/c2,
but direct measurement of the Higgs has thus far eluded all efforts.
Currently, the CDF and D0 experiments at Fermilab are pushing to probe
the mass regions not excluded by LEP with a number of analyses optimized
for masses extending from 100 to 200 GeV/c2. Near the LEP boundary where
the Higgs is expected to decay primarily to a pair of bottom quarks, the
most promising channels involve Higgs produced in association with a W
or Z boson. In particular, the ZH modes have very interesting properties
which can be taken advantage of at the analysis level. The mode in
which the Z decays to electrons or muons is extremely "clean", as leptons
from vector boson decay are typically well measured and all final state
particles are directly reconstructed. Conversely, the mode in which the Z
decays to neutrinos is extremely challenging, as the presence of the Z can
only be inferred from momentum imbalance provided by recoil with the Higgs.
Utilizing new analysis techniques developed to isolate a Higgs signal
amongst its seemingly overwhelming backgrounds, no significant excess of
signal has currently been observed. However, limits have been set on the
production cross section of a Higgs boson. Currently, limits of 16 times
the standard model expectation has been set in the ZH->llbb mode, and 8
times the standard model expectation in the ZH->vvbb mode for a Higgs
mass of 115 GeV/c2. Combining these results with all low mass analyses
at CDF and D0, the Tevatron has placed a limit of 3.7 times the standard
model expectation directly above LEP's lower mass limit. |
|
Wednesday, May 7, 2008
|
|
Huicheng Guo
[Host: Bob Hirosky]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Leptogenesis in a model of dark energy and dark matter” |
|
Wednesday, April 16, 2008
|
|
Enrico Lunghi
[Host: Bob Hirosky ]
|
|
3:30 PM, Room 204
|
|
Fermilab |
| Physics Building |
|
“Light charged Higgs at the beginning of the LHC era” |
ABSTRACT:
| I will review the experimental evidence and theoretical biases that point to physics beyond the Standard Model. In the context of realistic supersymmetric models, I will explore in detail some interesting theoretical issues and investigate whether existing experimental constraints still allow for a light extended Higgs sector. Predictions at Tevatron and LHC in such scenarios are explored.
|
|
Wednesday, February 20, 2008
|
|
Reserved for Colloquium
|
|
3:30 PM, Room 204
|
|
|
| Physics Building |
|
|
ABSTRACT:
| I report on two topics presented at the PHYSTAT 2007 conference at CERN.
1) Event weighting has long been used, but is typically maligned (under the rubric of the "method of moments") as statistically inefficient (producing parameter estimates with worse uncertainty) compared to maximum likelihood fitting. However, event weighting is quite fast, requiring only one pass through the data with no iteration. Further, it has fairly recently been understood that the choice of weight function has a substantial effect on the errors, and by choosing to minimize the parameter error via calculus of variations, near-ideal uncertainty can result.
2) Evaluation of systematic errors in MC is a tedious fact of life; it's slow. We have for generations done it one variable at a time. However, it turns out that doing so makes us blind to certain systematic effects--even when the systematic errors themselves are uncorrelated. And it also turns out that statisticians knew about this since the 1920's. I'll show what our method blinds us to.
|
|
Wednesday, October 24, 2007
|
|
Kaustubh Agashe
[Host: Bob Hirosky]
|
|
3:30 PM, Room 204
|
|
University of Maryland |
| Physics Building |
|
“Signals for Composite Higgs models in top/W/Z physics” |
ABSTRACT:
| In the first part of the seminar, I will briefly review how the idea
of the Higgs boson being a composite particle of new strong dynamics
can explain the hierarchy between the Planck and weak scales
and how quarks and leptons being partially composite accounts for their
basic structure as well. I will argue that the largest experimental signals
for such a scenario arise in the top/W/Z sectors. Remarkably, this scenario
might have a dual and more useful description in terms of a warped higher
dimensional spacetime. So, in the second part of the seminar, I will focus on
computing signals for such composite Higgs models at the upcoming Large
Hadron Collider using the extra dimensional description. Specifically, I will
consider detection of the excitations (called Kaluza-Klein modes) of the
gluon and graviton in the extra dimension. |
|
Wednesday, October 17, 2007
|
|
Dmitri Tsybychev
[Host: Bob Hirosky]
|
|
3:30 PM, Room 204
|
|
Stony Brook |
| Physics Building |
|
“Results on mixing, Δ Γ s and related CP violation in B s meson system at Tevatron” |
ABSTRACT:
| The CDF and D0 experiments have collected large samples of hadronic and semileptonic
decays of B s mesons. We present the latest results from the Tevatron
on the measurement of mixing parameter Δ m s and the width difference between
B H s and B L s and the latest results on indirect CP violation in the B s meson system. |
ABSTRACT:
| Although the neutral kaon system has been researched many times in the
past, it still remains a vital tool for decisive studies on CP violation and
for probing into new physics. The KTeV experiment has played a crucial
role in these endeavors with an intense source of high energy kaon decays
coupled with a high precision detector. Currently, there's no published
calculation inside the Standard Model for Br(K L 0 -> π 0 π 0 μ + μ - ),
although the decay is possible via a virtual photon or a 'possible' new
neutral boson X 0 , which was recently observed by the HyperCP Experiment
in the decay Σ + -> pX 0 -> p μ + μ - . The decay K L L -> π 0 μ + μ - is also an intriguing study since it contains a direct CP
violating parameter. I shall report on the progress made in analyzing
these two decays.
|
|
Wednesday, April 18, 2007
|
|
Petar Maksimovic
[Host: Brad Cox]
|
|
3:30 PM, Room 204
|
|
John Hopkins University |
| Physics Building |
|
“Discovery of Σb” |
ABSTRACT:
| In recent months, the Tevatron reached a significant milestone
and delivered over one fb-1 to both the D0 and CDF experiments. The
large sample of data and a powerful displaced vertex trigger
combine to give CDF the world’s largest sample of fully
reconstructed Λb0s. Using this sample, we observe four new
Λb0 π+/- resononances, consistent with the hypothesis of
the lowest-lying Σb* baryon states.
|
|
Wednesday, April 11, 2007
|
|
Po-Shan Leang
[Host: E. Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Non-Abelian Plasma Instabilities” |
Special Colloquium
ABSTRACT:
| Neutron beta decay is the simplest of all nuclear beta decay. Its simplicity allows properties of neutron decay to be related directly to the weak coupling constants and thus precision measurements of neutron decay correlations and lifetime offer both sensitive checks of the Electroweak Standard Model as well as excellent probes of new physics. One question of intense interest is the nature of the observed baryon-antibaryon asymmetry of the universe. In this talk I will focus on a sensitive search for new time reversal invariance violating physics which offers the potential of illuminating this mystery. |
Nuclear/Particle Seminar
|
Wednesday, February 28, 2007
|
|
Steffen Strauch
[Host: Simonetta Liuti]
|
|
3:30 PM, Room 204
|
|
University of South Carolina |
| Physics Building |
|
“Polarization Transfer in 4He(e,e'p): Is the Ratio G_Ep/G_Mp Modified in the Nuclear Medium?” |
|
Wednesday, February 21, 2007
|
|
Daniel Cronin-Hennessy
[Host: E. Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of Minnesota |
| Physics Building |
|
“CLEO-c: A New Frontier of Weak and Strong Interactions” |
ABSTRACT:
| The Cornell Electron-positron Storage Ring (CESR) upgrade has provided a
high luminosity dataset in the charm threshold region. Among the goals
of the CLEO-c experiment are precision measurements of charm leptonic and
semileptonic decay rates. These data are used to confront lattice-QCD
predictions for hadronic decay constants and form factors. Validation of
lattice-QCD will allow for improved CKM constraints. I will overview the
goals of the CLEO-c ecxperiment and report recent progress. |
|
Wednesday, January 31, 2007
|
|
Caglar Dogan
[Host: E. Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Bulk Viscosity of High Temperature QCD” |
ABSTRACT:
| The data obtained from RHIC experiments is reproduced pretty well by ideal
hydrodynarnical models. However, the first corrections to perfect fluid behavior are also
important in interpreting the data and are characterized by shear and bulk viscosities, I
will explain the perturbative calculation of the bulk viscosity of high-temperature QCD
using kinetic theory to leading order in the coupling constant. This fills a gap in the
literature since even a parametric estimate of this quantity was absent prior to OUT work.
Although it may not be justified to apply our results to the strongly coupled plasma
produced at RHIC, we hope that they will at least provide the right order of magnitude. |
|
Wednesday, January 17, 2007
|
|
Lisa Everett
[Host: Peter Arnold]
|
|
3:30 PM, Room 204
|
|
Univeristy of Wisconsin |
| Physics Building |
|
“Cabibbo Haze in Lepton Mixing” |
|
Wednesday, December 13, 2006
|
|
Reading Day
|
|
3:30 PM, Room 204
|
|
N/A |
| Physics Building |
|
“N/A” |
|
Wednesday, November 22, 2006
|
|
Thanksgiving Recess
[Host: N/A]
|
|
3:30 PM, Room 204
|
|
N/A |
| Physics Building |
|
“N/A” |
|
Wednesday, November 8, 2006
|
|
Patrick Toale
[Host: E. Craig Dukes]
|
|
3:30 PM, Room 204
|
|
Penn State |
| Physics Building |
|
“IceCube: A Cubic Kilometer Neutrino Telescope” |
ABSTRACT:
| The IceCube neutrino telescope, located deep in the glacial ice at the geographic
South Pole, is the worlds largest neutrino observatory. The primary goal of
IceCube is the detection of high energy neutrinos of astrophysical origin. In its
second year of construction, IceCube now includes its predecessor, AMANDA.
This talk will cover the science goals, design, and construction of IceCube, along
with recent results from AMANDA. |
|
Wednesday, October 25, 2006
|
|
Qinghai Wang
[Host: Paul Fendley]
|
|
3:30 PM, Room 204
|
|
Unversity of Connecticut |
| Physics Building |
|
“Worldline Instantons and Pair Production” |
ABSTRACT:
| The imaginary part of the QED effective action can be approximated by the contribution of a worldline instanton, a solution to the classical Euclidean worldline equations of motion. In this talk, I will briefly review this formalism and compute also the prefactor arising from quantum fluctuations about this classical path. I will show the excellent agreement between our semiclassical approximation, conventional WKB, and numerical results using numerical worldline loops. I will also show the extension of the worldline instanton technique to multidimensional spatially inhomogeneous electric background fields, for which, WKB failed to apply.
|
|
Thursday, October 12, 2006
|
|
Stefan Gruenendahl
[Host: E. Craig Dukes]
|
|
4:00 PM, Room 313
|
|
Fermilab |
| Physics Building |
|
“The Dark Energy Survey” |
|
Wednesday, September 20, 2006
|
|
Andrew J. Norman
[Host: E. Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Hadronic Particle Production and the Future of Neutrino Physics” |
|
Wednesday, May 3, 2006
|
|
Yaogang Lian
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Small Instantons in CP1 and CP2 Sigma Models ” |
|
Wednesday, April 26, 2006
|
|
Patrick Keith-Hynes
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Hairpin Diagrams and the Planar Equivalence of One-Flavor QCD and N=1 Supersymmetric Yang-Mills Theory” |
|
Wednesday, April 19, 2006
|
|
Jeff Nelson
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
William & Mary |
| Physics Building |
|
“First MINOS Results from the NuMI Neutrino Beam” |
ABSTRACT:
| The Main Injector Neutrino Oscillation Search (MINOS) experiment
recently completed its first year of exposure to the NuMI neutrino beam.
In this run muon neutrinos produced at Fermilab near Chicago were
directed 734.3km through the Earth to the 5,400 ton MINOS far detector
located a half mile underground in the Soudan Underground Laboratory in
northern Minnesota. This talk will describe the performance of the NuMI
neutrino and the MINOS detectors during this initial run and will
include presentation of preliminary data from this initial data run.
|
|
Wednesday, April 12, 2006
|
|
Mehrdad Adibzadeh
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Models of Neutrino Masses in Extra Dimensions” |
|
Wednesday, April 5, 2006
|
|
Roy Briere
[Host: Dinko Počanić]
|
|
3:30 PM, Room 204
|
|
Carnegie Mellon University |
| Physics Building |
|
“Charm Physics from CLEO-c” |
ABSTRACT:
| The CLEO-c physics program includes studies of D(s) mesons and charmonium.
Precision results are of interest for weak flavor physics, including
verification of lattice QCD. Many results for D0 and D+ are already
available, and Ds data taking has begun recently. Charmonium data and
the energy scan used to find a Ds running point offer QCD and
spectroscopy results as well.
I will introduce the CLEO-c program, and illustrate its impact with
a selection of recent results and future plans.
|
Joint Nuclear/High Energy Physics Seminar
|
Wednesday, March 15, 2006
|
|
Matthew Wingate
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Washington |
| Physics Building |
|
“Accurate Lattice Calculations for Quark Flavor Physics” |
ABSTRACT:
| Lattice QCD calculations now include the effects of 2 light sea quarks and 1 strange sea quark through the use of an improved staggered fermion action; consequently, calculations important to quark flavor physics are free of the unsystematic errors that infected previous calculations. Furthermore, the work of the previous decade to reduce discretization errors, to tame lattice perturbation theory, to control light quark mass extrapolations, and to implement
heavy lattice quarks is finally converging to yield realistic, accurate calculations. In this talk I discuss some important recent innovations we employ, show tests of the methodology, and present our current results. I conclude by showing the impact of the results on constraints of Standard Model parameters and by mapping the route for further improvement.
|
|
Wednesday, March 8, 2006
|
|
****SPRING RECESS****
|
|
3:30 PM, Room 204
|
|
|
| Physics Building |
|
|
Special High Energy Seminar
|
Wednesday, February 1, 2006
|
|
Rodney Crewther
[Host: P.Q. Hung]
|
|
3:30 PM, Room 204
|
|
University of Adelaide |
| Physics Building |
|
“Axion Phenomenology” |
ABSTRACT:
| The best explanation for the lack of CP violation by strong interactions involves the existence of axions: light, weakly interacting spin-0 particles. The PVLAS experiment, hep-ex/0507107, reports seeing a rotation of the polarization of 0.1 W laser light in a transverse magnetic field consistent with having an axion but with an extremely large (unlikely?) ratio of electromagnetic to color anomalies. JLab's FEL Axion group plans to use its 10 kW free-electron laser to provide a rigorous check on the PVLAS result and to look for photon regeneration due to propagating axions. I will review the reasons for having axions and explain why experiments of this type are so important.
|
This is a joint Nuclear-High Energy seminar
|
Wednesday, January 18, 2006
|
|
Vladimir Pascalutsa
[Host: Cole Smith]
|
|
3:30 PM, Room 204
|
|
The College of William and Mary /Jefferson Lab - Theory Group |
| Physics Building |
|
“Chiral Effective-Field Theory in the Resonance Region” |
ABSTRACT:
| I will discuss the chiral effective-field theory of QCD can be extended to the Delta-resonance energy region. This framework
will then be applied to the pion electroproduction, radiative pion electroproduction, and Compton scattering with the aim
of a model-independent study of the Delta-resonance properties.
These results will be contrasted with the state-of-the-art lattice QCD studies.
|
|
Wednesday, November 30, 2005
|
|
Scott Ranson
[Host: P.Q. Hung]
|
|
3:30 PM, Room 204
|
|
NRAO |
| Physics Building |
|
“Using Exotic Pulsars to Probe Fundamental Physics” |
ABSTRACT:
| Over the past several years, deep searches with the world's largest radio telescopes have uncovered several truly exotic pulsar systems. Observations of these objects using the incredibly precise techniques of pulsar timing, allow us to
probe regimes of gravitational, electromagnetic,
plasma, and particle physics that are impossible
to reach in laboratories here on earth. In this talk I'll discuss several of the most interesting recent discoveries and show how they are onstraining gravitational theories, plasma physics, and the physics of matter at supranuclear densities.
|
|
Wednesday, November 23, 2005
|
|
****THANKSGIVING BREAK****
|
|
3:30 PM, Room 204
|
|
|
| Physics Building |
|
|
Joint Nuclear/High Energy Seminar
|
Wednesday, November 16, 2005
|
|
Robert Michaels
[Host: Donal Day]
|
|
3:30 PM, Room 204
|
|
Thomas Jefferson National Accelerator Facility, USA |
| Physics Building |
|
“208Pb Radius Experiment -- PREX” |
ABSTRACT:
| The difference between the neutron radius Rn of a heavy nucleus and the proton radius Rp is believed to be several percent. This neutron skin has proven to be elusive to pin down experimentally in a rigorous fashion. The proposed Lead Radius Experiment PREX will measure the parity-violating electroweak asymmetry in the elastic scattering of polarized electrons from 208Pb at an energy of 850 MeV and a scattering angle of 6 degrees. Since the Z0 boson couples mainly to neutrons, this asymmetry provides a clean measurement of Rn with a projected experimental precision of ±1%. In addition to being a fundamental test of nuclear theory, a precise measurement of Rn pins down the density dependence of the symmetry energy of neutron rich nuclear matter which has impacts on neutron star structure and atomic parity violation experiments. |
|
Wednesday, October 12, 2005
|
|
Manfred Paulini
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
Carnegie Mellon University |
| Physics Building |
|
“Recent B Physics Result from CDF” |
ABSTRACT:
| We discuss selected heavy flavour physics results from the Collider
Detector at Fermilab (CDF) operating at the Run II Tevatron Collider at
Fermilab. We focus on the search for particle-antiparticle oscillations in
the system of neutral Bs0 mesons which is one of the high priority
analyses of the CDF B physics program in Run II.
|
|
Wednesday, May 4, 2005
|
|
Drew Baden
[Host: Robert Hirosky]
|
|
3:30 PM, Room 204
|
|
University of Maryland |
| Physics Building |
|
“Status of the CMS Experiment” |
|
Wednesday, April 27, 2005
|
|
Saeed Ahmad
[Host: Hank Thacker]
|
|
3:00 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Study of CP(N) Models” |
*Please note special date, time, and location.
|
Thursday, April 14, 2005
|
|
Nathanial Tagg
[Host: Craig Dukes]
|
|
2:30 PM, Room 313
|
|
Oxford University |
| Physics Building |
|
“Neutrino Oscillations and the MINOS Experiment” |
ABSTRACT:
| Neutrinos have started to gain enormous attention over the last 30 years
because of strange properties that allow them to seemingly disappear when
travelling long distances. I will give brief history of the important
discoveries by neutrino experiments to put the newly-started MINOS
experiment into context. MINOS is an experiment to produce neutrinos at
Fermilab (near Chicago) and fire them undgeround to the Soudan lab (near
Duluth), a baseline of 730km. The challenges of performing this
long-baseline neutrino oscillation experiment will be discussed.
|
|
Wednesday, April 6, 2005
|
|
Bill Louis
[Host: P.Q. Hung]
|
|
3:30 PM, Room 204
|
|
LANL |
| Physics Building |
|
“Searching for Neutrino Oscillations: Early Results from MiniBooNE” |
ABSTRACT:
| The MiniBooNE experiment at Fermilab is designed to be a definitive test of the LSND evidence for neutrino oscillations. If the LSND evidence is
confirmed, then, together with the results from solar, reactor, and atmospheric neutrino oscillation experiments, it would imply Physics Beyond the Standard Model, such as sterile neutrinos, CPT/Lorentz violation, or mass-varying
neutrinos. After two and a half years of operation, MiniBooNE has collected about 500K neutrino events and is clearly observing charged-current quasi-elastic events, charged-current pion events, neutral-current pi0 events, and neutral-current elastic events. Some of these early, non-oscillation physics
results will be presented along with the prospects for the future. |
|
Wednesday, March 30, 2005
|
|
Tim Holmstron
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
|
| Physics Building |
|
“HAPPEX: Looking for Strange Quark Structure in the Nucleon” |
|
Wednesday, March 23, 2005
|
|
E. Paschos
[Host: Brad Cox]
|
|
3:30 PM, Room 204
|
|
University of Dortmund, Germany |
| Physics Building |
|
“Leptogenesis with Massive Neutrinos Abstract” |
ABSTRACT:
| Leptogenesis provides an attractive first step for creating the Baryon Asymmetry in the Universe. The couplings of heavy Neutrinos contain, in
general, Dirac and Majorana mass terms which break the CP symmetry. Their decays produce a lepton asymmetry which subsequently is converted into a
baryon asymmetry. Models with this property and their implications for neutrino experiments and structure formation in the universe will be
discussed. |
|
Wednesday, March 9, 2005
|
|
Chung-Wen Kau
[Host: Blaine Norum]
|
|
3:30 PM, Room 204
|
|
NCSU |
| Physics Building |
|
“Plan Polarizability and Chiral Effective Theory” |
|
Wednesday, March 2, 2005
|
|
David Smith
[Host: Brad Cox]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“The Search for KL-> 2&pi 0&gamma” |
ABSTRACT:
| The decay KL-> 2π 0γ is interesting as a probe of the sixth order of chiral perturbation theory. I am currently searching for this decay using data collected by the KTeV experiment in 1997. The decay is swamped by 3π0background events with one missing photon. Using Monte Carlo simulations of the two modes, I have designed cuts to eliminate this background while retaining signal events. The current upper limit on the decay is 5.6*10-6; my current single event sensitivity is 2.19*10-7 with only one background event remaining for one flux of data. I hope to extend this work to the 1999 data while retaining this low SES and background level. |
See Suzie Garrett
|
Wednesday, January 26, 2005
|
|
***RESERVED**
|
|
3:30 PM, Room 204
|
|
|
| Physics Building |
|
“**TBA**” |
|
Wednesday, January 19, 2005
|
|
Vo Van Thuan
[Host: P. Q. Hung]
|
|
2:00 PM, Room 204
|
|
Institute for Nuclear Science and Technology, Hanoi |
| Physics Building |
|
“Status of Nuclear Physics and High Energy Research in Vietnam” |
Joint with High Energy/Nuclear
|
Wednesday, December 8, 2004
|
|
Christian Weiss
[Host: Simonetta Liuti]
|
|
3:30 PM, Room 204
|
|
Jefferson Laboratory |
| Physics Building |
|
“3D Parton Imaging of the Nucleon in High Energy pp and pA Collisions” |
|
Thursday, December 2, 2004
|
|
Matteo Palutan
[Host: Sergio Conetti]
|
|
3:30 PM, Room 204
|
|
Laboratori Nazionali di Frascati |
| Physics Building |
|
“Recent Results From KLOE at DAFNE” |
ABSTRACT:
| Recent results obtained by the KLOE experiment at the phi-factory DAFNE will be presented. They mainly concern neutral kaon physics including rare K_S decays, K_L lifetime and branching ratio's; a comprehensive discussion of the measurements that bear on the extraction of Vus will be given. The study of scalar and pseudoscalar meson production in radiative phi decays and the measurement of the e+e- hadronic cross section using the initial state radiation will also be reviewed. |
|
Wednesday, November 3, 2004
|
|
HyangKyu Park
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Michigan |
| Physics Building |
|
“The Decay Σ+ → pµ+µ- and Possible New Physics from HyperCP” |
ABSTRACT:
| The Fermilab HyperCP (E871) experiment collected on the order of 1010 hyperon decays in 1997 and 1999 runs. Using the entire data set, we will report on the observation of events with reconstructed masses consistent with that of Σ+ assuming the final state pµ+µ-. The observed events would be the rarest decay ever observed in the baryon sector. Possible interpretations of the observed events will be discussed. Finally we will present a speculation for a new physics scenario. |
|
Friday, October 29, 2004
|
|
Rob Pisarski
[Host: Hank Thacker]
|
|
12:00 PM, Room 313
|
|
Brookhaven National Lab |
| Physics Building |
|
“Gross-Witten Point and Deconfinement in Matrix Models” |
|
Wednesday, October 20, 2004
|
|
Mike Longo
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of Michigan |
| Physics Building |
|
“A High Statistics Search for the Theta-plus Pentaquark” |
ABSTRACT:
| There have been many reported sightings of exotic strange five-quark baryons in the past two years. Using the HyperCP dataset, which includes the largest K-short sample ever taken, we have searched for Theta-plus(1.54) -> K-zero + proton
decays, with a spectrometer with excellent mass resolution.
|
|
Wednesday, October 13, 2004
|
|
Radu Marginean
[Host: Bob Hirosky]
|
|
10:00 AM, Room 123
|
|
Ohio State |
| HEP Conference Room |
|
“A Neural Network Analysis of the Top Cross Section at CDF” |
|
Tuesday, October 12, 2004
|
|
Abaz Kryemadhi
[Host: Bob Hirosky]
|
|
1:30 PM, Room 123
|
|
University of Indiana |
| HEP Conference Room |
|
“Lambda_c and Lambda_b Measurements From FOCUS and D0” |
|
Wednesday, September 29, 2004
|
|
Rick Jesik
[Host: Bob Hirosky]
|
|
3:30 PM, Room 204
|
|
Imperial College, London |
| Physics Building |
|
“Beautiful B Physics at DO” |
|
Wednesday, September 22, 2004
|
|
David Richards
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
J Lab |
| Physics Building |
|
“Hadron Structure from Lattice QCD” |
|
Wednesday, September 15, 2004
|
|
Alexander Kaganovich
[Host: P.Q. Hung]
|
|
3:30 PM, Room 204
|
|
Ben Gurion University |
| Physics Building |
|
“Some Old Puzzles of Particle Physics and Cosmology in the Light of the the Two Measures Theory” |
|
Friday, May 21, 2004
|
|
Bill Molzon's
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
University of California at Irvine |
| Physics Building |
|
“The MECO Experiment to Search for Mu N- ---> e- N with 10-17 Sensitivity” |
ABSTRACT:
| The Muon to Electron Conversion (MECO) experiment is designed to detect the coherent conversion of muons to electrons in the field of a nucleus if this process occurs as infrequently as once for 10-17 muons that are captured in a muonic atom. To date, no examples of muon and electron number violating transitions have been seen in charged lepton processes, and MECO will improve the sensitivity of past searches by 3-4 orders of magnitude. MECO has sufficient sensitivity to discover this muon-number violating process if it occurs at rates predicted in several well-motivated models for physics beyond the Standard Model, e.g. a broad class of grand-unified supersymmetric models. I will briefly discuss the motivation for and status of searches for lepton flavor violating (LFV) processes and the status of other experiments under construction, and then describe the MECO experiment. I will concentrate on recent progress on some technical aspects of the experiment and present the prospects for its construction and operation. |
|
Wednesday, April 28, 2004
|
|
Barry Holstein
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Massachusetts |
| Physics Building |
|
“Effective Interactions are Effective Interactions” |
ABSTRACT:
| The use of effective field theory techniques will be discussed and
applications given in classical and quantum mechanics, in condensed matter
physics, in QCD, and in quantum gravity. |
|
Wednesday, April 21, 2004
|
|
Swapan Chattopadhyah
[Host: Blaine Norum]
|
|
3:30 PM, Room 204
|
|
JLab |
| Physics Building |
|
“To the Frontiers of HighField/High Energy Density Physics and Ultrafast Processes via Energy Recovering Linacs” |
|
Wednesday, April 7, 2004
|
|
Michael Ronquest
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Search For New Direct CP Violation in Neutral Kaon Decays” |
|
Wednesday, March 24, 2004
|
|
Ngoc-Khanh Tran
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Many New Faces of Extradimension Theory” |
|
Wednesday, January 21, 2004
|
|
V. Jejjala
[Host: Paul Fendley]
|
|
3:30 PM, Room 204
|
|
Virginia Tech |
| Physics Building |
|
“Deconstruction and the Cosmological Constant” |
|
Monday, January 5, 2004
|
|
Mike Strickland
[Host: Peter Arnold]
|
|
3:30 PM, Room 204
|
|
Techische Universitat , Vienna |
| Physics Building |
|
“Collective Modes of an Anisotropic QGP” |
ABSTRACT:
| In this talk I will discuss the collective modes of a quark-gluon plasma which has a momentum-space anisotropy in the quark and/or gluon districution functions. I will derive the hard thermal loop gluon self-energies using classical kinetic theory for anistropic systems and show that in addition to the normal stable aluonic quasiparticle modes there exist also unstable gluonic quasiparticle modes which can affect the thermalization and isotropization of a quark-gluon plasma. I will then demonstrate how the anisotropic HTL gluonic self-energy can be used to calculate the directional dependence of the heavy quark energy loss in an anisotropic QGP. Along the way I will also talk a bit about the isotopic limit and demonstrate that the heavy quark energy loss obtained is never negative. |
|
Wednesday, November 12, 2003
|
|
Imran Younus
[Host: Craig Dukes]
|
|
4:00 PM, Room 204
|
|
Syracuse University |
| Physics Building |
|
“Precision Measurement of the Weak Mixing Angle in Parity-Violating Moller Scattering” |
ABSTRACT:
| SLAC E158 is an experiment to measure the parity non-conserving asymmetry in Moller scattering. Longitudinally polarized 48 GeV electrons are scattered off unpolarized (atomic) electrons in a liquid hydrogen target with an average Q2 of 0.027 GeV2. The asymmetry in this process is proportional to the weak mixing angle. The preliminary results give APV = –151.9 +/– 29.0(stat) +/– 32.5(syst) parts per billion. For the sine of the weak mixing angle 0.2371 +/– 0.0025 +/– 0.0027, which is consistent with the Standard Model prediction (0.2386 +/– 0.0006). |
|
Wednesday, October 22, 2003
|
|
Andrew Norman
[Host: Craig Dukes]
|
|
3:30 PM, Room 204
|
|
College of William and Mary |
| Physics Building |
|
“Measurement of the Branching Fraction for K-long -> mu+ mu- e+ e-” |
ABSTRACT:
| This seminar will describe the measurement of decay of the long lived neutral kaon into two muons and two electrons. The measurement was performed using the data taken during experiment E871 which ws performed on the B5 beamline at the Alternating Gradient Synchrotron (AGS) of the Brookhaven National Laboratory (BNL).(For a complete abstract, please see posted announcement in the Physics Bldg. ) |
SPECIAL HIGH ENERGY SEMINAR.
Please note day and time!!
|
Monday, August 18, 2003
|
|
Kim Splittorff
|
|
3:00 PM, Room 313
|
|
State University of New York, Stony Brook |
| Physics Building |
|
“Elitzur's theorem and the sign problem” |
ABSTRACT:
| Elitzur's theorem stating the impossibility of spontaneous breaking of
local symmetries in a gauge theory is reexamined. The existing proofs of
this theorem rely on gauge invariance as well as positivity of the weight
in the Euclidean partition function. We examine the validity of Elitzur's
theorem in gauge theories for which the Euclidean measure of the partition
function is not positive definite. We find that Elitzur's theorem does not
follow from gauge invariance alone. We formulate a general criterion under
which spontaneous breaking of local symmetries in a gauge theory is
excluded. Finally we illustrate the results in an exactly solvable two
dimensional abelian gauge theory. |
Please note special room and time
|
Wednesday, May 7, 2003
|
|
Dr. Bonnie Fleming
[Host: Lanchun Lu]
|
|
4:00 PM, Room 313
|
|
FermiLab |
| Physics Building |
|
“FINeSE: Fermilab Intense Neutrino Scattering Experiment” |
ABSTRACT:
| The Booster neutrino beamline at Fermilab provides the world's highest
intensity neutrino beam in the 0.5-1.0 GeV energy range. There is a
wealth of neutrino physics that can be accomplished using this beam in
addition to the oscillation physics already underway. A 10 ton
detector located at 100 meters from the recently commissioned Booster
neutrino source would definitively measure the strange quark
contribution to the nucleon spin. In addition, it would also
complement the existing MiniBooNE oscillation experimental program by,
along with MiniBooNE data, making an improved measurement of the search
for muon neutrino disappearance in a region of particular interest to
cosmologists. FINeSE will also be able to investigate
neutrino-scattering cross sections at low energy, in a region where
there is growing interest in neutrino scattering interactions. This
physics program and the FINeSE detector will be presented. |
Special Nuclear and High Energy
|
Wednesday, April 16, 2003
|
|
Prof. Xiangdong Ji
[Host: Xiaotong Song]
|
|
3:00 PM, Room 204
|
|
Univ. of Maryland |
| Physics Building |
|
“Viewing the nucleon through "color" filters” |
ABSTRACT:
| While the form factors and parton distributions provide separately
the shape of the proton in coordinate and momentum spaces, a more
powerful imaging of the proton structure can be obtained through
phase-space distributions. In this talk, I introduce the Wigner-type
quark and gluon distributions which depict a full-3D proton at every
fixed light-cone momentum, like what is seen through momentum
("color")-filters. After appropriate phase-space reductions, the
Wigner distributions are related to the generalized parton distributions
(GPD's) and transverse-momentum dependent parton distributions, which
are measurable in high-energy experiments. The new interpretation of
GPD's provides a classical way to visualize the orbital motion of the
quarks, which is known to be the key to the spin and magnetic moment
of the proton. |
|
Wednesday, April 9, 2003
|
|
Carston Vogt
[Host: J. Lenaghan]
|
|
3:00 PM, Room 204
|
|
Nordita |
| Physics Building |
|
“Photon emission from dense quark matter in compact stars” |
ABSTRACT:
| Quark matter at large baryon density is characterised by
a colour-flavour-locked phase where chiral symmetry is
broken. This leads to the appearance of the light octet of
Goldstone bosons. At temperatures below the gap which
results from quark pairing, the light Goldstone bosons are
the dominant degrees of freedom and provide the main
source for photon emission. We calculate photon emission
rates from scattering of Goldstone bosons and discuss
possible observational consequences of our results for
compact stars featuring colour-superconductivity. |
|
Wednesday, April 2, 2003
|
|
Andrea Soddu
[Host: P. Q. Hung]
|
|
3:00 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Phenomenology of a mass matrix from six dimensions” |
ABSTRACT:
| A model with two compactified extra spatial dimensions is introduced.
A mass matrix with democratic structure, a common Yukawa coupling for
the three families and all the matrix elements of the same order of
magnitude, is derived.
The mass spectrum and CKM matrix obtained in a ten parameter version
of the model will be presented together with a possible scenario
which could solve the Strong CP problem without axions. |
|
Wednesday, March 26, 2003
|
|
Thomas Curtwright
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Miami |
| Physics Building |
|
“Developments in time evolution” |
ABSTRACT:
| Properties of quantum Nambu-brackets are studied in various physical situations. The brackets are shown to define time evolution in ways that can be quite novel, perhaps even very unusual, but which are nonetheless always fully consistent. The key physical ideas are to use different time scales on different invariant sectors of a system, and to
conjoin time evolution with symmetries of the system's dynamics. For finite times, this formulation of time-development is not the usual
unitary transformation, but nonetheless it gives results from which conventional, unitarily evolved data can be recovered. The methods are applicable to quantum field theory, perhaps the physical deas more generally than the Nambu brackets.
|
|
Wednesday, March 19, 2003
|
|
Gert Aarts
[Host: Peter Arnold]
|
|
3:00 PM, Room 204
|
|
Ohio State University |
| Physics Building |
|
“Transport coefficients in hot field theory” |
PLEASE NOTE SPECIAL TIME
|
Wednesday, February 19, 2003
|
|
Adam Lewandowski
[Host: Donal Day]
|
|
3:30 PM, Room 204
|
|
Johns Hopkins |
| Physics Building |
|
“Running with the Radius in RS1” |
ABSTRACT:
| We find a renormalization group formalism in the compactified
Randall-Sundrum scenario with the renormalization scale set by the radius
of the compact space. Couplings on the hidden brane run with the size of
the space. We use this formalism to demonstrate the
stability of the hierarchy. |
|
Wednesday, February 5, 2003
|
|
Prof. Robert Hirosky
[Host: Brad Cox]
|
|
3:00 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Panning for Gold (or Finding your physics in a torrent of data)” |
ABSTRACT:
| Interesting physics interactions occur copiously at high energy hadron
colliders. However, these events are often swamped by background
interactions with rates many orders of magnitude greater. Further,
bandwidth and storage constraints require O(10^5-10^6) or greater real
time data rejection for collecting data samples. This talk will review
the 'Trigger' or real time data selection strategies used in the D-Zero
experiment at Fermilab and review the "golden" physics channels sought in
the Run 2 collider program. |
|
Wednesday, December 4, 2002
|
|
Jonathan Lenaghan
[Host: H. Thacker]
|
|
3:00 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Mesoscopic QCD and the Theta-Vacua” |
ABSTRACT:
| The partition functions of gauge theories with spontaneously broken
chiral symmetries are analyzed for an arbitrary number of flavors, N_f,
and arbitrary quark masses including the contributions from all
topological sectors in the Leutwyler--Smilga regime. In the
Leutwyler--Smilga regime, the theories only depend on simple
combinations of quark masses, volume, chiral condensate and vacuum
angle. We consider the cases of quarks in the adjoint and fundamental
representation separately. For two and three flavors, the \theta
dependence of the QCD vacuum is studied in detail. We find a
discontinuity at \theta=\pi in the first derivative of the energy
density with respect to \theta for degenerate quark masses. This
corresponds to the first--order phase transition in which CP is
spontaneously broken, known as Dashen's phenomena. We derive simple
expressions for the chiral condensate and the topological density and
show that they are in fact related. By examining the zeros of the
various partition functions, we elucidate the mechanism leading to
Dashen's phenomena in QCD. |
|
Wednesday, October 9, 2002
|
|
Djordje Minic
[Host: Paul Fendley]
|
|
3:00 PM, Room 204
|
|
Virginia Tech |
| Physics Building |
|
“Holographic Renormalization Group, Time and String Theory” |
|
Wednesday, May 1, 2002
|
|
Craig Dukes
[Host: H. Thacker]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“The CKM Experiment at Fermilab: Attacking the CKM Matrix Using Charged Kaons” |
ABSTRACT:
| The CKM (Charged Kaons at the Main injector) collaboration is
planning a new Fermilab experiment whose goal is to measure the Cabibbo,
Kobayashi, Maskawa matrix element V(td) with a statistical precision of 5%.
This is done through the measurement of the branching ratio of the
ultra-rare charged kaon decay: K+ -> pi+ nu nu. This measurement will
play a critical role in testing the Standard Model hypothesis that the
sole source of CP violation in nature resides in the imaginary parts of
the Cabibbo, Kobayashi, Maskawa matrix elements. Attacking this question
in the kaon sector is both experimentally and theoretically independent of
the ongoing programs to measure these same parameters in the B meson sector.
To make this challenging measurement a novel decay-in-flight spectrometer
has been designed. I will discuss the physics, the spectrometer, and give
the status of the experiment. |
|
Wednesday, April 17, 2002
|
|
Bogdan Morariu
[Host: Paul Fendley]
|
|
3:30 PM, Room 204
|
|
Rockefeller University |
| Physics Building |
|
“Quantum mechanics on noncommutative Riemann surfaces” |
|
Wednesday, April 10, 2002
|
|
Paul Frampton
[Host: P. Q. Hung]
|
|
3:30 PM, Room 204
|
|
University of North Carolina, Chapel Hill |
| Physics Building |
|
“Zeroes of the neutrino mass matrix” |
Joint Nuclear/High Energy
|
Wednesday, November 7, 2001
|
|
Raju Venugopalan
[Host: S. Liuti]
|
|
12:45 PM, Room 313
|
|
Brookhaven National laboratory |
| Physics Building |
|
“Melting the Color Glass Condensate in Heavy Ions Collisions” |
|
Wednesday, October 31, 2001
|
|
Antonio Delgado
[Host: Marcos-Seco]
|
|
12:45 PM, Room 313
|
|
Johns Hopkins University |
| Physics Building |
|
“Electroweak Breaking from the Bulk of Extra Dimensions” |
|
Friday, August 17, 2001
|
|
Heinrick Paes
[Host: P. Q. Hung]
|
|
2:00 PM, Room 313
|
|
Vanderbilt University |
| Physics Building |
|
“Absolute neutrino mass determination” |
|
Wednesday, May 16, 2001
|
|
Deitrich Bodeker
[Host: Peter Arnold]
|
|
3:30 PM, Room 204
|
|
Brookhaven National Laboratory |
| Physics Building |
|
“A local Langevin equation for slow long distance modes in hot Yang-Mills” |
|
Wednesday, May 2, 2001
|
|
Xuepeng Sun
|
|
3:30 PM, Room 204
|
|
UVA |
| Physics Building |
|
“Monte Carlo Simulation of Phase Transition in 3D O(N) Phi-4 theory” |
Special High Energy Seminar
|
Thursday, April 26, 2001
|
|
Sang-Joon Lee
[Host: Harry Thacker]
|
|
4:00 PM, Room 204
|
|
University of Minnesota |
| Physics Building |
|
“A Measurement of the (D+ --> K-bar*0 l+ nul) (D+ --> K-bar0 l+ nul) Branching Fractions” |
|
Wednesday, April 25, 2001
|
|
Alexander Golossanov
[Host: H. Thacker]
|
|
3:30 PM, Room 204
|
|
UVA - High Energy Physics |
| Physics Building |
|
“Physics of Decay KL --> pi+pi-e+e- at kTeV” |
|
Wednesday, April 18, 2001
|
|
Svyatoslav Tkachenko
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Virginia - Department of Physics |
| Physics Building |
|
“The phase transition temperature of relativistic phi-4 theory” |
|
Wednesday, April 11, 2001
|
|
John Shields
|
|
3:30 PM, Room 204
|
|
UVA-High Energy Physics |
| Physics Building |
|
“Physics of KL --> pi+pi- gamma at Ktev” |
Special Physics/Astronomy
|
Wednesday, February 21, 2001
|
|
Lars Bildsten
[Host: P. Q. Hung]
|
|
3:30 PM, Room 204
|
|
ITP, Santa Barbara |
| Physics Building |
|
“Gravitational Radiation from Accreting Neutron Stars: Implications for Millisecond Pulsar Formation and LIGO” |
|
Wednesday, November 29, 2000
|
|
Marcos Seco-Miquelez
[Host: H. Thacker]
|
|
3:30 PM, Room 204
|
|
UVA - Department of Physics |
| Physics Building |
|
“Baryogenesis in the MSSM” |
|
Wednesday, November 15, 2000
|
|
Tim Holmstrom
[Host: Hank Thacker]
|
|
3:30 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Measuring CP violation in Hyperons” |
|
Wednesday, October 4, 2000
|
|
Robert Rossmanith
[Host: Blaine Norum ]
|
|
3:00 PM, Room 204
|
|
Forschungszentrum Karlsruhe |
| Physics Building |
|
“High Power EUV Radiation Sources for Lithography” |
|
Wednesday, August 2, 2000
|
|
Martin Mojzis
[Host: Ivan Horvath]
|
|
3:00 PM, Room 313*
|
|
Comunius University, Bratislava |
| Physics Building |
|
“Reordering the Chiral Expansion - Solution of the Old Puzzle” |
|
Monday, June 12, 2000
|
|
Professor Tatsuya Nakada
[Host: Brad Cox]
|
|
3:00 PM, Room 204
|
|
CERN and Paul Scherrer Institute |
| Physics Building |
|
“Present Status of LHCb An Experiment to Make Precision Studies of CP Violation in Beauty Hadron Decays” |
SPECIAL HIGH ENERGY SEMINAR
|
Friday, April 28, 2000
|
|
Howard Georgi
[Host: P. Q. Hung]
|
|
2:00 PM, Room 203
|
|
Harvard University |
| Physics Building |
|
“Dynamically Broken Topcolor - Building Higgs Bosons without Other Higgs Bosons” |
Joint Nuclear/High Energy
|
Wednesday, March 22, 2000
|
|
Geoffrey Court
[Host: Donald Crabb]
|
|
3:00 PM, Room 204
|
|
University of Liverpool |
| Physics Building |
|
“An Update on Nucleon Spin Structure Measurements at HERMES” |
Special Nuclear/HEP Seminar
|
Thursday, March 9, 2000
|
|
Prof. Sibaji Raha
[Host: P. K. Kabir]
|
|
3:30 PM, Room 204
|
|
Bose Institute, Calcutta and Brookhaven National laboratory, Upton, NY |
| Physics Building |
|
“QCD and Dark Matter” |
|
Wednesday, March 8, 2000
|
|
Professor Konrad Kleinknecht
[Host: Brad Cox]
|
|
3:00 PM, Room 204
|
|
Johannes Gutenberg University, Mainz, Germany |
| Physics Building |
|
“Recent Results from the NA48 Kaon Decay Experiment at CERN” |
ABSTRACT:
| The origin of the violation of CP (particle-antiparticle) symmetry in
decays of neutral K mesons has been unclear for a long time after its
discovery. The question is whether this violation is due to a new superweak
interaction or to a small part of the well-known weak interaction.
An experiment at CERN in 1988 (NA31) indicated that epsilon', the parameter
that distinguishes between the two possibilities, is different from
zero, thus pointing to the latter possibility, while an experiment at FNAL
found a result consistent with zero. NA48 has measured the parameter
epsilon'/epsilon of direct CP violation and confirms the earlier observation
of NA31. Results will be given, as well as some results on rare Kaon decays.
Postcript: This result was announced for the first time on March 7th
at CERN. This will be the first North American discussion
of this crucial measurement which points to the origin of CP
(time reversal) violation.
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Wednesday, March 1, 2000
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John McCune
[Host: Hank Thacker]
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3:00 PM, Room 204
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University of Virginia |
| Physics Building |
|
“Chiral Symmetry and Long Wavelength Dirac Eigenmodes in QCD” |
Joint Nuclear - High Energy Seminar
|
Wednesday, February 23, 2000
|
|
Tom Cohen
[Host: J.V. Noble]
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3:00 PM, Room 204
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University of Maryland |
| Physics Building |
|
“Effective and Ineffective Field Theory in Nuclear Physics” |
Special High Energy Seminar
|
Thursday, February 17, 2000
|
|
Pedro Mercadente
[Host: P. Q. Hung]
|
|
4:00 PM, Room 204
|
|
Florida State University |
| Physics Building |
|
“Supersymmetry Breaking in SO(10) models” |
Special High Energy Seminar
|
Wednesday, February 16, 2000
|
|
Ben White
[Host: P. Q. Hung]
|
|
4:15 PM, Room 204
|
|
University of Swansea |
| Physics Building |
|
“The Angular Momentum Sum-Rule - - - Spin-Doctoring the Proton” |
|
Wednesday, February 16, 2000
|
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Peter Arnold
|
|
3:00 PM, Room 204
|
|
University of Virginia |
| Physics Building |
|
“Efferctive theories of electroweak baryon number violation” |
|
Wednesday, December 8, 1999
|
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Carl Carlson
|
|
3:00 PM, Room 204
|
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College of William and Mary |
| Physics Building |
|
“Excited Baryons in Large Nc QCD” |
|
Wednesday, December 1, 1999
|
|
Igor Musatov
|
|
3:00 PM, Room 204
|
|
Old Dominion University |
| Physics Building |
|
“Non-forward Parton Distribution and Deeply Virtual Compton Scattering” |
Joint Nuclear/High Energy
|
Wednesday, November 17, 1999
|
|
Cynthia Keppel
[Host: S. Luiti]
|
|
3:00 PM, Room 204
|
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Hampton University / Jefferson Lab |
| Physics Building |
|
“Quark-Hadron Duality - Recent results from Jefferson Lab” |
|
Wednesday, October 20, 1999
|
|
Bill Bardeen
[Host: Thacker/Horvath]
|
|
3:00 PM, Room 204
|
|
Fermilab |
| Physics Building |
|
“Weak Matrix Elements in the Large Nc expansion of QCD ” |
|
