Energy loss effects on charm and bottom production in high-energy heavy-ion collisions

We study the effect of energy loss on charm and bottom quarks in high-energy heavy-ion collisions including longitudinal expansion and partial thermalization. We find that high $p_\perp$ heavy quarks are greatly suppressed, and consequently, high-mass dileptons from heavy quark decays are also suppressed. We consider the detector geometry and single lepton energy cuts of the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because of the longitudinal expansion, the suppressions of $ee, e\mu$ and $\mu\mu$ pairs resulting from the heavy quark energy loss are very different due to the different rapidity coverages and energy cuts. The assumed energy loss, $dE/dx=-2$ GeV/fm, results in a larger suppression of dielectrons from charm decays than those from bottom decays but both will fall below the Drell-Yan yield at high invariant mass. We also study the effect of energy loss on single leptons from heavy quarks decays.