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

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.