In-Medium Vector Mesons, Dileptons and Chiral Restoration

Ralf Rapp

doi:10.1063/1.3542032

paper

In-Medium Vector Mesons, Dileptons and Chiral Restoration

arXiv:1010.1719 · doi:10.1063/1.3542032

Abstract

Medium modifications of the electromagnetic spectral function in hadronic and quark-gluon matter are reviewed. A strong broadening of the $ρ$ meson, which dominates the spectral function in the low-mass regime, is quantitatively consistent with dilepton excess spectra measured in photoproduction off cold nuclei (CLAS/JLab) and in fixed-target ultrarelativistic heavy-ion collisions (NA45,NA60/CERN-SPS). The large excess observed by PHENIX at RHIC remains unexplained to date, but is most likely not due to emission from the Quark-Gluon Plasma. Connections to thermal lattice QCD promise progress in the search for chiral symmetry restoration.

9 pages, 12 figures, Proceedings of Chiral 2010 (Valencia, June 21-24, 2010)