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Direct photons from Au+Au collisions at RHIC: QGP vs. hot hadronic gas

A. K. Chaudhuri
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Abstract

We have analysed the preliminary PHENIX data on the transverse momentum distribution of direct photons in 0-20% centrality Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV. In ideal hydrodynamics, data are explained if Au+Au collision produces Quark-Gluon-Plasma at the temperature $T_i$=400 MeV, at an initial time $τ_i$=0.6 fm. PHENIX data are not explained in the alternate scenario when Au+Au collisions produces hot hadronic gas with initial temperature within physically acceptable limit.

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A. K. Chaudhuri. 2005-12-10. Direct photons from Au+Au collisions at RHIC: QGP vs. hot hadronic gas. https://arxiv.org/abs/nucl-th/0512032

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