Indiana University High Energy Physics

and Astrophysics Seminars

2002-2003 Academic Year
 

Mondays, 4pm  Refreshments 3:30 pm
Swain West 238 HEP Coffee Room (SW262)




 

Fall Semester 2002
 
 
 

Sep. 2: NO SEMINAR THIS WEEK
Labor Day


 

Sep. 9: Results from ICHEP, Part 1
Mark Messier
Indiana University


 

Sep. 16: Results from ICHEP, Part 2
Andrzej Zieminski
Indiana University


 

Sep. 23: Results from ICHEP, Part 3
Daria Zieminska
Indiana University


 

Introduction to 'Little Higgs' Models
Mike Berger
Indiana University


 

Sep. 30: Petrov classification in five dimensions and black holes on cylinders
Pieter-jan De Smet
Stony Brook

We give a five-dimensional version of the well-known Petrov classification of metrics on four-dimensional space-times. Subsequently, we use this classification to look for the metric of a black hole in a Kaluza-Klein background within the class of algebraic special metrics.


 

Oct. 7: A lattice determination of the effective potential for the Polyakov loop
Travis Miller
Indiana University

Simulations of pure SU(3) gauge theory indicate deconfinement phase transition at high temperatures. The order parameter for this tranistion is the trace of the Polyakov loop. The transition is known to be weakly first order, and the effective mass of the Polyakov loop is very small near the transition. Therefore the dynamics of the Polyakov loop dominate the free energy above the deconfinement temperature and so a Landau-Ginsberg free energy functional in terms of the Polyakov loop will give a good description of the bulk thermodynamic properties of the deconfined state. Using non-equilibrium lattice simulations, the parameters of the effective potential are determined at several temperatures in the deconfined phase.


 

Oct. 14: Supernova Neutrinos
Chuck Horowitz
Indiana University

Core collapse supernovae are gigantic explosions of massive stars that synthesis chemical elements, accelerate cosmic rays, and form neutron stars and black holes. They are macroscopic systems dominated by the weak interactions, radiating fully 99% of their energy in neutrinos. This provides a unique opportunity to search for large scale signatures of the symmetries and features of the weak interactions. This talk is a gentle introduction to supernovae followed by a discussion of how neutrino interactions in dense matter, neutrino oscillations, and other neutrino properties determine the neutrino spectrum. I will also discuss how heavy element nucleosynthesis may be influenced by the neutrinos. Finally, I discuss the detection of supernova neutrinos, including new detectors based on neutrino-nucleus elastic scattering. The next galactic supernova should be a rich source of astrophysical and neutrino information.


 

Oct. 21: The Auger Experiment
Rishi Meyhandan
LSU

Recent experiments have suggested the existance of astrophysical particles of extreme energies ( > 10^20eV ) produced within a relatively close region to the Earth. However such sources do not appear to exist. The Pierre Auger Observatory intends to collect a significant amount of data at these energies to definitely show if this is true.


 

Oct. 28: Prospects for Higgs bosons discovery at the LHC
Ketevi Assamagan
Brookhaven National Laboratory

The observation of one or several Higgs bosons will be fundamental for the understanding of the electroweak symmetry breaking mechanism. In the Standard Model (SM), one scalar doublet is responsible for the electroweak symmetry breaking, leading to the prediction of one Higgs boson. The simplest extension to the SM Higgs sector is the two Higgs doublet model present in many extensions to the SM itself, including supersymmetry. In such models, symmetry breaking leads to five Higgs particles, three neutral and a charged pair. We briefly review the current experimental searches of the Higgs bosons, then discuss the sensitivity of the LHC detectors to their discovery.

Copy of transparencies


 

Nov. 4: Neutrino mixing and big bang nucleosynthesis
Nicole Bell
Fermilab

We analyze active-active neutrino mixing in the early universe and show that transformation of neutrino-antineutrino asymmetries between flavours is unavoidable when neutrino mixing angles are large. This process is a standard Mikheyev-Smirnov-Wolfenstein flavour transformation, modified by the synchronisation of momentum states which results from neutrino-neutrino forward scattering. The new constraints placed on neutrino asymmetries eliminate the possibility of degenerate big bang nucleosynthesis.

Implications of active-sterile neutrino mixing are also reviewed.


 

Nov. 11: Physics at a Photon Collider
Stefan Soldner-Rembold
Fermilab

High energy photon beams can be produced at a future Linear Collider by Compton backscattering of laser photons on the electron beams. After an introduction into the working principle of a Photon Collider, the highlights of the physics programme will be reviewed. The Photon Collider's physics potential is complementary to the electron-positron option of the Linear Collider. The `golden process' is the production of Higgs bosons in photon-photon collisions. Various Higgs scenarios accessible at a Photon Collider will be discussed.


 

Nov. 18: Neutrino Oscillation Results from the Sudbury Neutrino Observatory
Scott Oser
U. Penn

The Sudbury Neutrino Observatory (SNO) has determined the flavor content of the $^8$B solar neutrino flux by measuring the rates of charged current and neutral current neutrino interactions on deuterium. These results directly demonstrate neutrino flavor transformation at greater than $5\sigma$ significance. The total flux of $^8$ neutrinos is found to be in good agreement with solar model predictions. Measurements of the day and night neutrino energy spectra probe models of neutrino oscillation. A global fit of SNO data and results from other solar neutrino experiments to neutrino oscillation models strongly favors the Large Mixing Angle (LMA) MSW solution.


 

Nov. 25: NO SEMINAR THIS WEEK
Thanksgiving Week


 

Dec. 2: Physics with Fermilab Booster Neutrinos
Rex Tayloe
The Fermilab Booster Neutrino Beamline will be the world's most intense source of neutrinos in the 1 GeV energy region. The MiniBooNE experiment is using this source to search for neutrino oscillations as indicated by LSND. Additional nuclear and particle physics topics may also be investigated with a modest-sized detector at a near-source location. The current status of the neutrino beam and the MiniBooNE experiment will be presented along with plans to build a new experiment on the Booster Neutrino Beamline.


 

Dec. 9: Search for Extra Dimensions with CDF Using Missing Energy
Kevin Burkett
Harvard

Theories with large extra spatial dimensions have been proposed as a solution to the hierarchy problem. I will focus on the model of Arkani-Hamed, Dimopoulos, and Dvali, where gravity can propagate in the 4+n dimensional bulk of spacetime, while the rest of the SM fields are confined to a 3+1 dimensional brane. I will discuss the phenomenology of this model, foucusing on signatures for the detection of extra dimensions at colliders. I will then present results from the CDF experiment for a search for the direct emission of gravitons using data from Run I at the Tevatron.