"The Quest for Old Physics at RHIC"

Bill Zajc
Columbia University

Abstract

A few microseconds after the Big Bang, the dominant form of matter in the universe was a deconfined gas of quarks and gluons characterized by a temperature of order 200 MeV. One of the primary goals of the Relativistic Heavy Ion Collider (RHIC) is the creation and detection of nuclear matter at temperatures and densities approximating those found in the early universe. RHIC achieves this by colliding heavy nuclei at total center-of-mass energies approaching 40 TeV (for Au-Au collisions at 200 GeV per nucleon pair). The results from the first two years of RHIC operations have clearly established the collective dynamics of the particles produced in these high energy nuclear collisions, suggesting that it is possible to describe their behavior as a 'state of matter'. The measured temperatures and energy densities are also well within the regime where the transition to deconfined quarks and gluons is expected. I will present the results that support these conclusions, discuss the observation of 'jet quenching' and charm production, and describe the required control measurements which are underway.