η_c production and dimuon enhancement in heavy ion collisions

Dilepton production in heavy ion collisions, in the Intermediate Mass Region (IMR) has consistently shown an excess over theoretical estimates. An attempt to understand this discrepancy between the observed dilepton pairs and the theoretical estimate is made here through the production of the $\eta_c$ meson and estimates obtained by NRQCD calculations. We find that $\eta_c$ production offers a satisfactory quantitative picture for explaining the discrepancy.