General Colloquium:

February 21 - 4:00pm Phys 223
(Coffee at 3:30p.m. in room 242)

Alex R. Dzierba

Professor of Physics
Indiana University

Search for Gluonic Excitations

Abstract

An article in the science section of the New York Times appearing in August 2000 listed the "Ten Physics Questions to Ponder for a Millennium or Two" and one of those questions was: How can we understand quark and gluon confinement in quantum chromodynamics? Confinement comes about because flux tubes form between quarks, owing to the self-interaction of gluons. Within quark-antiquark bound states - mesons - the excitations of these flux tubes are expected to lead to a new spectrum of hybrid mesons. If the quark spins are aligned, the first excited state of the flux tube leads to mesons with quantum numbers that cannot be formed by simple quark-antiquark system. This these exotic hybrids are the 'smoking gun' characteristics of the spectrum of hybrids - or gluonic excitations. The exotic hybrids are expected to be produced when one uses photons as a probe. Until now, photon beams of the required flux, energy, polarization, spot size and emittance have not been available. The electron accelerator at Jefferson Lab will be upgraded in energy to 12 GeV and a new experimental hall and detector will be built to search for these gluonic excitations. This talk will review the physics and the status of the upgrade project and detector. This project is often referred to as the "Hall D Project" and has been described in a cover story article in American Scientist and another article in the CERN Courier.

Websites

American Scientist article: http://www.sigmaxi.org/amsci/articles/00articles/dzierba.html
Cern Courier article: http://www.cerncourier.com/main/article/40/7/16
Personal: http://dustbunny.physics.indiana.edu/~dzierba/
Hall D website: http://dustbunny.physics.indiana.edu/HallD/

Brief Bio

Alex received his BS in Physics from Canisius College in Buffalo, NY and his Ph D in experimental physics from the University of Notre Dame. He spent two years as Research Fellow and then two more years as Senior Research Fellow at the California Institute of Technology before joining the physics faculty at Indiana University in 1973 where he is a Professor of Physics. He served one year (1981-82) as a program officer for particle physics at the National Science Foundation and one year (1985-86) as Scientific Associate at CERN in Geneva, Switzerland. He also served on the Fermilab Users Group Executive Committee and chaired the Brookhaven Lab AGS/RHIC Users Executive Committee in 1992-94. He is a Fellow of the American Physical Society. From 1999 to 2001 he was president of the Indiana U Chapter of Sigma Xi. Alex was spokesman for experiments at Fermilab and Brookhaven and is now the spokesman for the Hall D collaboration. At Indiana University, Alex ia also a member of the Honors College Faculty and he developed a calculus-based honors physics course which he now teaches: http://dustbunny.physics.indiana.edu/~dzierba/hp221_2001/