Operation Of Relativistic Heavy Ion Collider Research Articles

Five years of tracking heavy ion collisions at RHIC

Five years have passed since the first collisions of Au nuclei at the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (BNL) on Long Island. With nucleon–nucleon center-of-mass energies of up to s NN = 200 GeV RHIC provides the highest energy heavy ion collisions at any existing collider. To study the dynamics of nuclear matter at extreme temperatures and pressures hundreds of produced particles need to be tracked and identified, which provides a sizable challenge to the four experiments. This article tries to summarize these first years of RHIC operation from the detector point of view and give a glimpse at the future of the accelerator and its experiments.

Formation of dense partonic matter in relativistic nucleus–nucleus collisions at RHIC: Experimental evaluation by the PHENIX Collaboration

Extensive experimental data from high-energy nucleus-nucleus collisions were recorded using the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). The comprehensive set of measurements from the first three years of RHIC operation includes charged particle multiplicities, transverse energy, yield ratios and spectra of identified hadrons in a wide range of transverse momenta ( p T ), elliptic flow, two-particle correlations, nonstatistical fluctuations, and suppression of particle production at high p T . The results are examined with an emphasis on implications for the formation of a new state of dense matter. We find that the state of matter created at RHIC cannot be described in terms of ordinary color neutral hadrons.