Seminar in Hadronic Physics

Thermal Bottomonium Suppression

Michael Strickland

Gettysburg College

I will discuss my recent work on thermal heavy quarkonium suppression. The thermal suppression of heavy quark bound states represents an ideal observable for determining if one has produced a quark gluon plasma in ultrarelativistic heavy-ion collisions. In recent years, however, a paradigm shift has taken place in the theory of quarkonium suppression due to new first principles calculations of the thermal widths of these states. These thermal widths are large, eg O(20-100 MeV) for the Upsilon, and cause in-medium suppression of the states at temperatures below their traditional disassociation temperatures. In order to apply the newly developed understanding to phenomenology, however, one must make detailed space-time models of the plasma including the effects of finite shear viscosity. These effects include not only the modification of the time evolution of the temperature of the system, flow, etc., but also the evolution of potentially large local momentum-space anisotropies which can dramatically affect the in-medium properties of the states. I will present comparisons of theory with data from RHIC 200 GeV/nucleon Au-Au collisions and LHC 2.76 TeV/nucleon Pb-Pb collisions.