Heavy-quark Langevin dynamics and single-electron spectra in nucleus-nucleus collision

TL;DR

This paper models heavy-quark dynamics in heavy-ion collisions using Langevin simulations, analyzing how their spectra are modified by the medium, and compares results with experimental data from RHIC.

Contribution

It introduces a comprehensive Langevin-based simulation framework that incorporates soft and hard collisions, nuclear effects, and medium evolution for heavy-quark transport in nucleus-nucleus collisions.

Findings

Reproduces RHIC non-photonic electron spectra.

Quantifies the impact of medium on heavy-quark spectra.

Provides transport coefficients from separate collision contributions.

Abstract

The stochastic dynamics of heavy quarks in the fireball produced in heavy-ion collisions is followed through numerical simulations based on the Langevin equation. The modification of the final p_T spectra (R_AA) of c and b quarks, hadrons and single-electrons with respect to pp collisions is studied. The transport coefficients are evaluated treating separately the contribution of soft and hard collisions. The initial heavy-quark spectra are generated according to NLO-pQCD, accounting for nuclear effects through recent nPDFs. The evolution of the medium is obtained from the output of two hydro-codes (ideal and viscous). The heavy-quark fragmentation into hadrons and their final semileptonic decays are implemented according to up to date experimental data. A comparison with RHIC data for non-photonic electron spectra is given.