Charged particle to photon ratio in heavy-ion collisions at RHIC: a different point of view

Abstract

We report an alternative explanation of the variation of charged particle to photon ratio in Cu+Cu collisions and Au+Au collisions from 1.4 $\pm$ 0.1 to 1.2 $\pm$ 0.1 at $\sqrt{s_{\mathrm{NN}}}$ = 62.4 GeV and 200 GeV respectively in STAR experiment at RHIC. Based on the theoretical predictions and experimental results we argue that the additional contribution of direct photons at $\sqrt{s_{\mathrm{NN}}}$ = 200 GeV in both Cu+Cu and Au+Au collisions are improving the ratio $\frac{N_{ch}}{N_{\gamma }}$ to 1.2 $\pm$ 0.1 from 1.4 $\pm$ 0.1.

20 pages , 7 figures

References in corpus (2)

• Measurement of direct photon production in p + p collisions at sqrt(s) = 200 GeV
• Rapidity dependence of the photon to pion production ratio in high energy collisions