Systematic studies of the centrality dependence of soft photon production in Au + Au collision with PHENIX

Centrality Dependence of J/ψ Production in Au+Au and Cu+Cu Collisions by the PHENIX Experiment at RHIC

J/ψ production has been measured in Au+Au and Cu+Cu collisions at √ sNN = 200 GeV by the PHENIX experiment at the Relativistic Heavy Ion Collider (RHIC) during 2004 and 2005, respectively, at mid-rapidity (|η| ≤ 0.35) via J/ψ → ee decay and at forward rapidity (1.2 ≤ |η| ≤ 2.2) via J/ψ → μμ decay. The nuclear modification factor (RAA) of J/ψ is presented as a function of the collision centralit...

Enhanced Direct Photon Production in Au + Au Collisions at √ s NN = 200 GeV in PHENIX

The production of electron pairs with p T between 1 and 5 GeV/c and m < 300 MeV has been measured at mid-rapidity in √ s N N = 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 fo...

Au + Au collisions in PHENIX

Direct Photon Production in Au+Au Collisions at RHIC-PHENIX Experiment

Direct photons have been measured with the PHENIX experiment in Au+Au collisions at √ sNN = 200 GeV. The direct photon result obtained with PHENIX-EMCal up to 18 GeV/c is consistent with the NLO pQCD calculation scaled by the nuclear overlap function. The measurement using internal conversion of photons into ee shows the enhancement of the yield comparing with NLO pQCD calculation.

Au+Au collisions with the PHENIX experiment at RHIC

Abstract. Thermal photons can provide information on the temperature of the new state of matter created at RHIC. In the pT region of 1–3 GeV/c thermal photons are expected to be the dominant direct photon source. Therefore, a possible excess compared to a pure decay photon signal due to a thermal photon contribution should be seen in the double ratio (γ/γ(π))Measured/(γ/γ(π ))Simulated, if suff...