Relativistic Heavy Ion Collision Studies with the RHIC STAR Experiment

Ohio State University Research Foundation -Do Not Use, Columbus OH

Investigators

Abstract

The main physics goals of this project are two-fold: 1) to create in the laboratory a new state of matter called "Quark Matter" by heating/ compressing normal nuclear matter to a sufficiently high temperature/ density, and, equally important, 2) to uniquely determine whether such a transformation to Quark Matter has actually taken place. Quark Matter is composed of "free" quarks and gluons, the fundamental particles which are bound into protons and neutrons which make up normal nuclear matter. It is predicted that the Universe was entirely in the Quark Matter state several millionths of a second after the Big Bang. The method which we will use to make Quark Matter will be to collide beams of heavy nuclei (e.g. lead on lead and gold on gold) moving at speeds near the speed of light. These beams will be generated by new state-of-the-art particle accelerators located at Brookhaven National Laboratory on Long Island and at the CERN laboratory in Geneva. To determine whether Quark Matter has actually been created in these high energy heavy ion collisions, large particle detectors will be present to detect the secondary particles which are produced (mostly pi and K mesons and a range of more exotic particles). Theories predict that unique signatures for Quark Matter formation can be extracted from information obtained from these secondary particles. One of the main roles of the Ohio State University group in these experiments is to lead the analysis of the data from a new type of particle detector which OSU has taken part in developing called a "Silicon Drift Detector" and, hopefully, to extract unique Quark Matter signatures.5