Quantifying Photoproduction Corrections to J/\psi Measurements in Au+Au and Cu+Cu Collisions at $\sqrt{s_{NN}} = 200$ GeV

Abstract

The contribution of J/\psi production from coherent and incoherent photon-induced production is calculated in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}} = 200$ GeV. The yield and nuclear modification factors ($R_{AA}$) contributed by photoproduction are presented as functions of transverse momentum ($p_T$) and centrality at both mid- and forward rapidity. The $R_{AA}$ of J/\psi from photoproduction is found to be as high as 0.6 in the lowest $p_{T}$ bin ($0 < p_{T} < 1$ GeV/$c$) at mid-rapidity in 60-92\% Au+Au collisions. The $R_{AA}$ measured in Au+Au and Cu+Cu collisions at $\sqrt{s_{NN}} = 200$ GeV are corrected by subtracting the calculated photoproduction contribution.