Indiana University High Energy Physics

and Astrophysics Seminars

1999-2000 Academic Year
 

Mondays, 4pm  Refreshments 3:30 pm
Swain West 251 HEP Coffee Room (SW262)


 

Fall Semester 1999
 
 
 

Aug. 30:

 

 Spin effects at high energies
Mauro Anselmino
Turin U./INFN Turin
 Many high energy hadronic processes have unexpected spin dependences, which do not reflect the simplicity of the spin perturbative QCD dynamics. Several examples are illustrated, with particular attention to single spin asymmetries in inclusive production of pions.

 


 

Sep. 6: NO SEMINAR THIS WEEK
Labor Day


 

Sep 13:

 

 b-quark and Onium Production
Andrzej Zieminski
Indiana University

We review the production of b-quarks and onia particles in different processes and compare experimental results from the Tevatron collider, fixed target experiments, LEP and HERA with the Next to Leading Order QCD calculations and with various models for onia production. This talk was originally given as a plenary talk at the '99 Physics in Collision conference in Ann Arbor.

 


 
 

Sep 20: 

 

 R-parity violation and single top squarks at the Tevatron
Zack Sullivan
Argonne National Lab

I will describe a new method for discovering heavy top squarks at Run II of the Tevatron if R-parity-violating supersymmetry exists, and the suprisingly strong bounds on baryon-number-violating couplings that may be derived from Run I data.


 
 

 Sep 27:


 

Oct 4:

 

 Weak Boson Fusion Higgses at the LHC
Dave Rainwater

Fermilab
 We demonstrate the feasibility of several previously overlooked observation channels for intermediate-mass (100-200 GeV) Higgses at the LHC. One of these channels, H -> WW, is likely to be the discovery mode if M_H > 120 GeV. Another, H -> tau tau, could provide the first Higgs-fermion coupling measurement, and also provides a No-Lose Theorem for observation of at least one of the CP-even neutral MSSM Higgses.


 

Oct 11:

 


 

Oct 18:

 

 The Top Quark as a Conspirator in the Electroweak Symmetry Breaking
Tim Tait
Argonne National Lab

I will discuss various attractive theories which give the top quark some kind of special role in the mechanism of the electroweak symmetry breaking, including both perturbative and non-perturbative ideas. Having motivated the careful study of the top quark, I will then discuss an overview of the information about top available from hadron colliders, in particular Run II of the Fermilab Tevatron, including t tbar production, single top producation, top decays, and polarization observables.


 

 Oct 25:

 


 

Nov 1:

 

 Prospects for Higgs Searches at the Tevatron
John Hobbs

Stony Brook
The feasibility for finding Higgs bosons during the upcoming Tevatron running has been studied by a working group with participants from both the theoretical and experimental communities. The mass range between 100 GeV and 200 GeV was considered, and both standard model and supersymmetric Higgs production was explored. The working group concluded that Higgs discovery is possible over most of this mass range using data samples corresponding to integrated luminosities of 20 inverse femtobarns per experiment.


 

 Nov 8:

 

 Limits on Quark Compositeness from High Energy Jets in PbarP Collisions at 1.8 TeV
Fred Borcherding

Fermilab
This talk describes the analysis employed at D0 to use the scalar sum of jet energies, Ht, from events at PbarP collisions at $\sqrt{s} = 1.8$~TeV, in setting limits on quark substructure.

Following this talk, there will be a more informal presentation: "Level 1 D0 Upgrade Central Tracker Trigger": The D0 Upgrade detector will have Level 1 triggers based on the Central Fiber Tracker, Central Preshower Detector and Forward Preshower Detector. These triggers share a common hardware design, which will be outlined in this talk.


 Nov 10:

(2 pm)

 

 e/pi separation in the ATLAS transition radiation detector
Andrea Manara

Indiana University
The seminar will deal about electron/pion separation in the ATLAS Transition Radiation Tracker. The standard way in which this has been achieved so far uses information from transition radiation. I will show results from a Geant simulation that suggest the possibility to improve this separation by using also information from dE/dx, over a wide range of momenta. I will show also results from September 99 beam test with 5GeV pion and electron beams and discuss data/MC comparison. This method could also help in separating K/pi, providing a useful tool for studying B-decays in ATLAS.


 Nov 15:

 

 Energy conditions --- Implications and limitations
Matt Visser

Washington University, St. Louis

The energy conditions of general relativity permit one to deduce very strong and general theorems about the behaviour of strong gravitational fields. However, the energy conditions are beginning to look much less secure that they once seemed --- there are quantum effects that violate all of the energy conditions, and there are even relatively benign looking classical systems (e.g., a conformally decoupled massless scalar field) that violate all the energy conditions. This opens up a Pandora's box of rather disquieting possibilites.
Nov 22: 

 

 NO SEMINAR THIS WEEK
Thanksgiving Week
 Nov 29:

 

 Search for Gluonic Excitations in Photoproduction---The Hall D Project at JLab
Alex Dzierba

Indiana University
The Hall D Project at JLab involves construction of a new beamline and experimental hall and detector to search for gluonic excitations - starting with exotic hybrids. In parallel, JLab plans an upgrade of the CEBAF accelerator to 12 GeV with the Hall D project being the impetus for this upgrade. The project will be reviewed by a committee of particle and nuclear physicists on Dec 6-7.

This seminar will review the physics motivation for the gluonic excitation search along with a description of the the detector design and accelerator upgrade.

Hall D Project website: http://dustbunny.physics.indiana.edu/HallD/


 Dec 6:

 

 Parametric Amplification of Gravitational Fluctuations During Preheating
Fabio Finelli

Purdue University
Cosmological perturbations can undergo amplification by parametric resonance during the preheating period following inflation, even on scales larger than the Hubble radius, without violating causality. A unified description of gravitational and matter fluctuations is crucial in order to determine the strength of the instability. To extract specific signatures of the oscillating inflaton field during preheating, it is essential to focus on a variable describing metric fluctuations which is constant in the standard analyses of inflation and which is used to predict the spectrum (the Bardeen parameter). Results and physical implications will be given for different inflationary models.


Dec 13:

 

 Classical-mechanics analogues for CP violation in the neutral-kaon system
Agnes Roberts

Indiana University
Nature is known to violate CP symmetry. Violation of CP and T occurs in the standard model, and there exists a standard-model extension in which CPT is also violated as a result of spontaneous symmetry breaking in an underlying fundamental theory. Several unsuccessful attempts have been made to create classical analogue models for CP violation. In this talk, I will discuss why those attempts were unsatisfactory and will present a classical analogue for spontaneous violation of CP and CPT.