Heavy quark dynamics in the QGP: R_AA and v_2 from RHIC to LHC

TL;DR

This paper investigates the behavior of charm and bottom quarks in quark-gluon plasma at RHIC and LHC, using a relativistic Langevin approach to predict observables like R_AA and v_2, and compares results with experimental data.

Contribution

It introduces a relativistic Langevin model with first-principle transport coefficients for heavy quark dynamics in QGP, linking microscopic theory with experimental observables.

Findings

Reproduces RHIC R_AA and v_2 data for heavy quarks

Provides predictions for LHC heavy quark observables

Demonstrates the effectiveness of the Langevin approach in QGP studies

Abstract

We study the stochastic dynamics of c and b quarks in the hot plasma produced in nucleus-nucleus collisions at RHIC and LHC, providing results for the nuclear modification factor R_AA and the elliptic flow coefficient v_2 of the single-electron spectra arising from their semi-leptonic decays. The initial QQbar pairs are generated using the POWHEG code, implementing pQCD at NLO. For the propagation in the plasma we develop a relativistic Langevin equation (solved in a medium described by hydrodynamics) whose transport coefficients are evaluated through a first-principle calculation. Finally, at T_c, the heavy quarks are made hadronize and decay into electrons: the resulting spectra are then compared with RHIC results. Predictions for LHC are also attempted.