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arXiv · 0906.1746

Enhanced Direct Photon Production in Au+Au Collisions at 200 GeV in PHENIX

S. Bathe
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Abstract

The production of electron pairs with transverse momentum between 1 and 5 GeV/c and m< 300 MeV has been measured at mid-rapidity in 200 GeV p+p and Au+Au collisions by the PHENIX experiment at RHIC. A significant excess above the hadronic background was observed in both p+p and Au+Au collisions. Treating the excess as internal conversion of direct photons, the direct photon yield in Au+Au was found to be enhanced compared to the binary-scaled p+p yield. The enhancement is consistent with an exponential inverse slope of 221 +- 23 +- 18 MeV and predictions from hydrodynamical models with initial temperature between 300 and 600 MeV at formation times of 0.6-0.15 fm/c.

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S. Bathe. 2009-06-09. Enhanced Direct Photon Production in Au+Au Collisions at 200 GeV in PHENIX. https://arxiv.org/abs/0906.1746

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