Net-Charge Fluctuations in Ultra-Relativistic Nucleus-Nucleus Collisions

Abstract: PHENIX is one of four experiments at the Relativistic Heavy-Ion Collider, RHIC. The high-energy heavy-ion collisions provided by this accelerator offer the possibility to study nuclear matter at high temperature and density. The high multiplicity of particles produced in these collisions puts high demands on detector performance. Providing space points along particle trajectories, the Pad Chamber detector system in PHENIX gives valuable information for charged particle tracking at midrapidity. In the collisions, nuclear matter is believed to undergo a phase transition to a state called the Quark-Gluon Plasma (QGP). In this state, quarks and gluons are not confined inside the hadrons, as in ordinary nuclear matter. In the search for such a deconfined phase, a lot of signatures has been suggested. One of those is based on information about the event-by-event net-charge fluctuations. These fluctuations have been studied in PHENIX at two different beam energies.