Search for the Quark-Gluon Plasma with Relativistic Heavy Ion Collisions

John C. Hill

Department of Physics,

Iowa State University

Ames, Iowa

A central goal of nuclear physics is to study a new form of high-temperature/density nuclear matter called the quark-gluon plasma (QGP).  It is believed that a microsecond after the birth of the universe it  was in the form of a QGP and later condensed by a phase transition of  unknown nature to nuclear matter as it exists today.  Temperatures  needed to convert nuclear matter to a QGP are around a factor of 1000  higher than those produced in a nuclear weapon.  First I will discuss
> the nature of the QGP which is a state of matter in which the quarks and gluons that compose nuclei are temporarily freed from their confinement within the nucleus.  I will then introduce you to the new accelerator called the Relativistic Heavy Ion Collider (RHIC) at  Brookhaven National Laboratory.  RHIC produces colliding beams of gold  nuclei with energies of 20,000 GeV and is our tool to find the QGP. We are part of the PHENIX detector collaboration where the emphasis is  on detecting and studying weak and electromagnetic probes such as  electrons, muons and photons that emerge from the collision fireball  reasonably uneffected by final-state interactions and thus give  important information about the initial phases of the collision.  After  illustrating the capabilities of PHENIX I will discuss possible signals for the QGP and conclude by sharing with you some results from RHIC's  first year of operation in 2000.