Nonperturbative Heavy-Quark Diffusion in the Quark-Gluon Plasma

TL;DR

This paper uses lattice QCD data and many-body theory to nonperturbatively calculate heavy-quark transport in the quark-gluon plasma, matching experimental observations and indicating a strongly coupled medium.

Contribution

It introduces a nonperturbative approach to compute heavy-quark diffusion coefficients using lattice QCD inputs within a Brueckner framework, applied to heavy-ion collision simulations.

Findings

Good agreement with experimental electron-decay spectra.

Supports the presence of a strongly coupled quark-gluon plasma.

Identifies bound and resonance states up to 1.5 T_c.

Abstract

We evaluate heavy-quark (HQ) transport properties in a Quark-Gluon Plasma (QGP) employing interaction potentials extracted from thermal lattice QCD. Within a Brueckner many-body scheme we calculate in-medium T-matrices for charm- and bottom-quark scattering off light quarks in the QGP. The interactions are dominated by attractive meson and diquark channels which support bound and resonance states up to temperatures of ~1.5 T_c. We apply pertinent drag and diffusion coefficients (supplemented by perturbative scattering off gluons) in Langevin simulations in an expanding fireball to compute HQ spectra and elliptic flow in \sqrt{s_{NN}}=200 GeV Au-Au collisions. We find good agreement with semileptonic electron-decay spectra which supports our nonperturbative computation of the HQ diffusion coefficient, suggestive for a strongly coupled QGP.