Low mass dilepton radiation at RHIC

Understand

In this work we discuss the emission of low mass dilepton radiation from a hydrodynamic evolution model of Au-Au collisions and make comparisons with recent PHENIX measurements.

• The dilepton emission rates from the hadronic phase are treated at finite temperature and baryon density and are completely constrained by broken chiral symmetry in a density expansion.
• The rates are expressed in terms of vacuum correlators which are measured in $e^+e^-$ annihilation, $\tau$ decays and photo-reactions on nucleons and nuclei.
• We consider two possibilities for the hadronic phase: A chemical equilibrated an off equilibrium hadronic gas.