Heavy Quark Diffusion with Relativistic Langevin Dynamics in the Quark-Gluon Fluid

TL;DR

This paper models heavy quark diffusion in quark-gluon plasma using relativistic Langevin dynamics with AdS/CFT-inspired drag, successfully matching experimental R_{AA} and v_{2} data for high-pT electrons.

Contribution

It introduces a relativistic Langevin framework with AdS/CFT-based drag for heavy quarks in QGP, combining hydrodynamics and diffusion simulations.

Findings

The drag force aligns with AdS/CFT predictions for high-pT electrons.

The model reproduces experimental R_{AA} and v_{2} data.

Heavy quark diffusion is effectively described by relativistic Langevin dynamics.

Abstract

The relativistic diffusion process of heavy quarks is formulated on the basis of the relativistic Langevin equation in It\^{o} discretization scheme. The drag force inside the quark-gluon plasma (QGP) is parametrized according to the formula for the strongly coupled plasma obtained by the AdS/CFT correspondence. The diffusion dynamics of charm and bottom quarks in QGP is described by combining the Langevin simulation under the background matter described by the relativistic hydrodynamics. Theoretical calculations of the nuclear modification factor R_{AA} and the elliptic flow v_{2} for the single electrons from the charm and bottom decays are compared with the experimental data from the relativistic heavy ion collisions. The R_{AA} for electrons with large transverse momentum (p_{T} > 3 GeV) indicates that the drag force from the QGP is as strong as the AdS/CFT prediction.