1. General Seminars

Thermal dileptons in QGP and non-ideal effects.

by Dr Sreekanth Villuvatath (Physical Research Laboratory, Ahmedabad, INDIA)

Aula Edificio 22 (Laboratori Nazionali di Frascati)

Aula Edificio 22

Laboratori Nazionali di Frascati

We study the \textit{non-ideal} effects arising due to viscosity (both bulk and shear), equation of state ($\epsilon\neq 3P$) and cavitation on thermal dilepton production from QGP at RHIC energies. The effect of bulk-viscosity and non-ideal equation of state are taken into account in a manner consistent with recent lattice QCD estimates. It is shown that the \textit{non-ideal} gas equation of state i.e $\epsilon-3P \neq 0$ behavior of the expanding plasma, which is important near the phase-transition point, can significantly slow down the hydrodynamic expansion and thereby increase the dilepton production-rates. We calculate the first order corrections to the dilepton production rates due to shear and bulk viscosities. It is shown that ignoring the cavitation can lead to a wrong estimation of the particle spectra. We show that the shear viscosity can enhance the thermal dilepton spectra whereas the bulk viscosity can suppress it. We present the combined effect of bulk and shear viscosities on the dilepton spectra