Impact of momentum-dependent drag coefficient on energy loss of charm and bottom quarks in QGP

TL;DR

This study models the momentum dependence of heavy-quark energy loss in quark-gluon plasma using polynomial expansions of the drag coefficient, improving the understanding of $R_{AA}$ for charm and bottom quarks in Pb-Pb collisions.

Contribution

Introduces a phenomenological polynomial expansion framework for the drag coefficient to better capture momentum dependence in heavy-quark energy loss models.

Findings

Enhanced agreement with experimental $R_{AA}$ data from ALICE and ATLAS.

Demonstrates sensitivity of heavy-quark observables to momentum-dependent transport coefficients.

Provides a flexible method to test different momentum dependencies in energy loss calculations.

Abstract

This paper investigates the influence of heavy-quark momentum on their interaction rate and the resulting drag coefficient in a quark-gluon plasma. To go beyond simplified treatments, we introduce a phenomenological extension of the drag coefficient by expressing the energy loss coefficients as polynomial expansions of momentum, thereby providing a flexible framework to test the sensitivity of heavy-quark observables to additional momentum dependence in transport coefficients. Furthermore, the effects of particle momentum on radiative and collisional energy loss are determined more accurately. The study focuses on calculating the nuclear modification factor ($R_{AA}$) of charm and bottom quarks in Pb-Pb collisions at $\sqrt{S_{NN}} = 5.02 \: TeV$. The initial distribution functions are evolved numerically using the Fokker-Planck equation. The results are compared with the latest experimental data from ALICE and ATLAS, collected in 2021 and 2022.