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

TL;DR

This paper develops an empirical model to understand charm quark energy loss in quark-gluon plasma, revealing the significance of collisional processes at RHIC and LHC energies and their impact on heavy meson production.

Contribution

It introduces a simple empirical approach to quantify charm quark energy loss due to multiple scatterings, aligning with experimental data and providing insights into azimuthal anisotropy.

Findings

Collisional energy loss accounts for up to half of charm quark energy loss at RHIC.

At LHC energies, collisional loss is about one third of total energy loss.

Energy loss may enhance low $p_T$ D-meson and electron production in AA collisions.

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. Best results are obtained when we approximate the momentum loss per collision $\Delta p_T \propto \alpha \, p_T$, where $\alpha$ 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 Langevin equation for heavy quarks we find that up to half of the energy loss of charm quarks at top 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 energy loss of charm quarks may lead to an enhanced production of D-mesons and single electrons at low $p_T$ in AA collisions.