# Heavy flavour Langevin diffusion with the chromo-electromagnetic field fluctuations in the quark-gluon plasma

## TL;DR

This paper investigates how fluctuations in the chromo-electromagnetic field influence heavy quark diffusion in quark-gluon plasma, using Langevin dynamics and comparing results with experimental data from RHIC and LHC.

## Contribution

It introduces a novel analysis of chromo-electromagnetic field fluctuations' impact on heavy quark diffusion within a relativistic hydrodynamic framework.

## Key findings

- Chromo-electromagnetic fluctuations significantly affect heavy meson R_AA.
- The model aligns well with experimental R_AA data at RHIC and LHC energies.
- Fluctuations improve the description of heavy quark energy loss.

## Abstract

The chromo-electromagnetic field is produced due to the motion of partons in a quark-gluon plasma created by relativistic heavy-ion collisions. The fluctuations in the produced chromo-electromagnetic field are important, since they cause heavy quarks to gain energy in the low velocity limit. We study the effect of such fluctuations on heavy quark diffusion in quark-gluon plasma within the framework of Langevin dynamics under the background matter described by the ($3+1$)-dimensional relativistic viscous hydrodynamics. Theoretical calculations of the nuclear modification factor ($R_{AA}$) of heavy mesons ($D$ and $B$ mesons), with the effect of these fluctuations, are compared with experimental measurements in $Au-Au$ collisions at $\sqrt{s_{NN}} = 200$ GeV by the STAR experiment at the BNL Relativistic Heavy Ion Collider (RHIC) and $Pb-Pb$ collisions at $\sqrt{s_{NN}} = 2.76$ and $5.02$ TeV by the ALICE and CMS experiments at the CERN Large Hadron Collider (LHC). We find a significant effect of these fluctuations in describing the the measured $R_{AA}$ of $D$ and $B$ mesons in both RHIC and LHC energies.