Heavy quark dynamics and hadronization in ultra-relativistic heavy-ion collisions: collisional versus radiative energy loss

TL;DR

This paper investigates heavy quark energy loss and hadronization in ultra-relativistic heavy-ion collisions, highlighting the roles of collisional and radiative processes, and compares results with experimental data from LHC and RHIC.

Contribution

It introduces an improved Langevin model incorporating gluon radiation for heavy quark energy loss and combines fragmentation and recombination for hadronization, providing a more comprehensive simulation framework.

Findings

Gluon radiation significantly contributes to heavy quark energy loss at high energies.

Recombination is crucial for heavy flavor meson production at intermediate energies.

Results align with experimental measurements of D meson flow and suppression at LHC and RHIC.

Abstract

We study the dynamics of energy loss and flow of heavy quarks produced in ultra-relativistic heavy-ion collisions within the framework of a Langevin equation coupled to a (2+1)-dimensional viscous hydrodynamic model that simulates the space-time evolution of the produced hot and dense QCD matter. The classical Langevin approach is improved such that, apart from quasi-elastic scatterings, radiative energy loss is incorporated by treating gluon radiation as an additional force term. The hadronization of emitted heavy quarks is simulated via a hybrid fragmentation plus recombination model. Our calculation shows significant contribution from gluon radiation to heavy quark energy loss at high energies, and we find the recombination mechanism is important for heavy flavor meson production at intermediate energies. We present numerical results for the nuclear modification and elliptic flow of D mesons, which are consistent with measurements at both LHC and RHIC; predictions for B mesons are also provided.