Relativistic Heavy Ion Physics
University of Tennessee, Knoxville

Relativistic Heavy Ion Physics

The research of the Relativistic Heavy Ion Physics (RHIP) group is focused on the study of nuclear matter at extreme temperatures and densities, which is an exciting field on the borderline between nuclear and high energy physics. At these extreme conditions of temperature and density nuclear matter will undergo a phase transition to a Quark-Gluon Plasma. In this new phase nuclear matter no longer consists primarily of protons and neutrons, but instead of deconfined quarks and gluons. Experimentally we are creating high-temperature nuclear matter by colliding heavy nuclei (heavy ions) at very high energies (ultrarelativistic energies) at nuclear accelerators.

Our group is participating in two experiments, PHENIX and ALICE. The PHENIX experiment is at the Relativistic Heavy Ion Collider (RHIC) and ALICE is at the Large Hadron Collider (LHC) at European Organization for Nuclear Research (CERN). PHENIX has been taking data since 2001, while ALICE started to take data in November 2010.

The progress in the field of dense and hot nuclear matter has often been described in the popular science literature. Articles in Scientific American and Physics Today from 2000 describe the claim by researchers from CERN to have found the Quark Gluon Plasma or at least to have seen very strong circumstantial evidence for it at center-of-mass energies around 20 A GeV. The more substantial evidence accumulated by the experiments at the Relativistic Heavy Ion Collider during the first three years of operation is laid out in articles in 2003 in Physics Today and CERN Courier. A more detailed description of our field can be obtained from overview talks at the Quark Matter conferences. Results from lower energy collisions at the AGS at BNL have been summarized by Ogilvie, while Lourenco has described the status of the results from the SPS at CERN. The RHIC results from PHENIX up to 2002 have been given by Zajc. The study of the spin structure of the proton is another focal point of our research. The prospects for this field at RHIC are described in an overview paper from 2000.