Probing Hot and Cold Nuclear Matter with Jets and Direct Photons at RHIC

Abstract:

I discuss highlights of the Relativistic Heavy Ion Collider (RHIC) program at Brookhaven National Lab, and the exciting discoveries there in recent years related to hard scattering events. Results have included the discovery of a suppression of nearly all high energy particle production due to Energy loss of jets in a hot QCD plasma formed in the collisions, and most recently quite exotic modifications of jet shapes for low energy jets (transverse momentum 1-5 GeV/c), which is accompanied by new hadronization processes. The important role of direct photons as "control" probes will also be discussed. Finally we give a survey of the landscape of the near future of heavy ion which will also involve experiments at the current energy frontier at the Large Hadron Collider, and also the study of another phenomena important to the understanding of basic hadron structure, also partly uncovered at RHIC, the "gluon saturation" effect.