Photons from Nucleus-Nucleus Collisions at Ultra-Relativistic Energies
Jan-e Alam, T. Hatsuda, Tapan K. Nayak, Pradip Roy, Sourav Sarkar, Bikash Sinha
Abstract
We compare the photon emission rates from hot hadronic matter with in-medium mass shift and Quark Gluon Plasma (QGP). It is observed that the WA98 data can be well reproduced by hadronic initial state with initial temperature \sim 200 MeV if the universal scaling of temperature dependent hadronic masses are assumed and the evolution of temperature with time is taken from transport model or (3+1) dimensional hydrodynamics. The data can also be reproduced by QGP initial state with similar initial temperature and non-zero initial radial velocity.