1210.3993 (Jajati K. Nayak et al.)

Electromagnetic signals from Au+Au collisions at RHIC energy,
$\sqrt{s_{NN}}$=200 GeV and Pb+Pb collisions at LHC energy,
$\sqrt{s_{NN}}$=2.76 TeV    [PDF]

Jajati K. Nayak, Bikash Sinha

We analyse the recently available experimental data on direct photon productions from Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV RHIC and from Pb+Pb collisions at $\sqrt{s_{NN}}$=2.76 TeV LHC energies. The transverse momentum ($p_T$) distributions have been evaluated with the assumption of an initial quark gluon plasma phase at temperatures $T_i$=404 and 546 MeV with initial thermalisation times $\tau_i$=0.2 and 0.1 fm/c respectively for RHIC and LHC energies. The theoretical evalutions agree reasonably well with the experimental observations. The thermal window for the LHC energy is justified through the ratio of the $p_T$ spectra of thermal photons to dileptons.

View original: http://arxiv.org/abs/1210.3993