Empirical determination of charm quark energy loss and its consequences for azimuthal anisotropy

Abstract

We propose an empirical model to determine the form of energy loss of charm quarks due to multiple scatterings in quark gluon plasma by demanding a good description of production of D mesons and non-photonic electrons in relativistic collision of heavy nuclei at RHIC and LHC energies. The best results are obtained when we approximate the momentum loss per collision ΔpT = α pT, where α is a constant depending on the centrality and the centre of mass energy. Comparing our results with those obtained earlier for drag coefficients estimated using the Langevin equation for heavy quarks, we find that up to half of the energy loss of charm quarks at the highest RHIC energy could be due to collisions while that at LHC energy at 2760 GeV/A the collisional energy loss could be about one-third of the total. Estimates are obtained for azimuthal anisotropy in momentum spectra of heavy mesons, due to this energy loss. We further suggest that the energy loss of charm quarks may lead to an enhanced production of D-mesons and single electrons at low pT in AA collisions.Communicated by SA Bass