Indiana University High Energy Physics

and Astrophysics Seminars

2004-2005 Academic Year
 

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

Organizers: Mike Berger and Mark Messier
 


 

Spring Semester 2005
 
 
 

Jan. 10: TBA


 

Jan. 17: NO SEMINAR THIS WEEK
Martin Luther King Jr Day


 

Jan. 21:
Friday
SW251
1 pm
Dark Energy
Jang Young Bang
(Indiana University)


 

Jan. 24: Reflections on Beauty: CP Asymmetries at Belle
Kay Kinoshita
(University of Cincinnati)

The Belle experiment, at the KEKB ring in Japan, aims to test the validity of the CKM mechanism in the Standard Model by measuring several aspects of CP violation in B meson decay. Belle has been running since June 1999, with over 350 million B events accumulated as of January 2005. We discuss one test of CKM through measurements via different processes of the same CP violating phase.


 

Jan. 31: Precision electroweak and top quark measurements at the energy frontier
Eva Halkiadakis
(Rochester)

The W and Z bosons, the top quark, and the yet-to-be-discovered Higgs boson are the most massive particles in the Standard Model. W and Z boson measurements are significant probes of the Standard Model and the prediction of the Higgs boson mass hinges on the precise measurements of the W boson and top quark masses. I will review the status of a few electroweak and top quark measurements from the CDF collaboration from the ongoing Run II of the Tevatron at Fermilab.


 

Feb. 4:
Friday
SW238
4 pm
The Top Quark: a Decade Since its Discovery
Ia Iashvili
(UC Riverside)

The top quark is by far the heaviest of all known fundamental particles. Its discovery in 1995 at Fermilab's Tevatron collider was the culmination of a search that had taken almost two decades, and involved hundreds of physicists. Since then the top quark remains subject of active investigations at the Tevatron, as unusually high mass of this particle is believed to hold clues for surprises, and possibly new discoveries.


 

Feb. 7:


 

Feb. 11:
Friday
SW238
4 pm
B physics at the Tevatron
Andrei Nomerotski
(Fermilab)

Since its discovery in 1977 the bottom quark played a prominent role in the Standard Model of elementary particles due to its heaviness and long lifetime. These unique features allowed to develop special approaches to study its properties both in theory and experimental techniques. The talk will review new results on B-physics from the DZero detector at Fermilab. The emphasis will be done on the lifetime and oscillation measurements which require precision tracking with silicon detectors.


 

Feb. 14: Precision and Energy Frontiers in Particle Physics: From CKM Measurements at CLEO to Supersymmetry at the Linear Collider
Karl Ecklund
(Cornell)

I describe my recent research on two frontiers of particle physics. At CLEO, on the precision frontier, measurements of semileptonic heavy meson decay help determine the Cabibbo-Kobayashi-Maskawa quark-mixing matrix and inform our understanding of the weak interaction and CP violation. I'll also describe the potential of a linear e+ e- collider at the energy frontier to determine the properties of supersymmetric particles and test cosmologically favored scenarios for neutralino dark matter.


 

Feb. 18:
Friday
SW238
4 pm
Measuring Top Quark Production Cross section with Dilepton Events
Peter Wittich
(U. Penn)

Almost ten years ago, the top quark was discovered at the Tevatron collider at Fermilab. With the small samples acquired at that time, we knew little about the top quark except that it is surprisingly massive.

Now, we are entering a stage where we are able to study this quark with large samples and precision measurements. I describe one of the first such measurements performed at CDF, the measurement of the production cross section of top quark pairs that decay into events with two leptons in the final state.


 

Feb. 21: B Meson Decays to Vector Particles: a New Window on Fundamental Interactions
Andrei Gritsan
(SLAC)

Fundamental particles and their interactions are the necessary building blocks in understanding our Universe, its existence and evolution. B-factory experiments produce abundant samples of B mesons to study fundamental interactions. CP-violation measurements can be represented on the "Unitarity Triangle." One angle of the triangle is now known to about 4%. The best measurements for the second angle were expected to come from the simple decay of a B meson into two pions. Instead, the best measurements have come from the decay of B mesons into a pair of spin-one resonances, B->rho rho. Another decay to a pair of vector mesons, B->phi K* is found to have polarization not consistent with expectations. Could this be a sign of New Physics? This opens a completely new approach to CP violation studies and search for New Physics.


 

Feb. 28:


 

Mar. 7:


 

Mar. 14: NO SEMINAR THIS WEEK
Spring Break


 

Mar. 21: The Lure of the Dark and Mysterious
Jon Thaler
(U. of Illinois)

I will give an overview of cosmology from an experimental particle physicist's perspective. The study of dark matter and dark energy is likely to have significant impact on particle physics ideas. Conversely, the non-zero neutrino mass has observable cosmological consequences. I am working on two astronomy projects that will address these issues, and more.


 

Mar. 28:


 

Apr. 4:


 

Apr. 11: Searches for Mesons with Gluonic Excitations
Ryan Mitchell
(Indiana U.)


 

Apr. 18: Perturbative QCD, the QGP and the interest in p-Nucleus Collisions
Walter Geist
(Strasbourg)

Predictions from perturbative QCD are generally well compatible with measurements. There are, however, still some open questions, such as gluon saturation at low x in DIS and the existence of the Quark-gluon-plasma. Based upon experimental results it will be argued that a thorough understanding of pA-collisions would be helpful for a more reliable interpretation of heavy-ion collisions.


 

Apr. 25:


 

Apr. 28:
Thursday
SW238
2:30 pm
The b-Quark: S Vertex of New Physics
Hal Evans
(Columbia University)

Signals of physics beyond the Standard Model are keenly anticipated in upcoming collider experiments. However, seeing a bump in a mass spectrum is only the first step on the path to a better model of particle interactions. Determining the nature of the new physics will require input from a wide variety of sources. One of the most promising of these turns out to arise from the flavor structure of quarks, particularly that of the b-quark. We will discuss why the study of b-quarks is such a fertile field for our understanding of physics beyond the Standard Model. Past successes as well as the current status of research will be outlined. We will then explore the next likely breakthrough in b-physics - the measurement of oscillations between Bs and anti-Bs mesons. Using work done on the DZero experiment at Fermilab, the challenges of this search will be highlighted and first, preliminary results will be presented. Along the way, we will see illustrations of how these challenges are being met in other areas of the study of B-hadrons at DZero.