Jet quenching at finite `t Hooft coupling and chemical potential from AdS/CFT

TL;DR

This work computes the jet quenching parameter $\hat{q}$ in strongly coupled gauge theories using AdS/CFT, extending the Liu–Rajagopal–Wiedemann holographic prescription to finite 't Hooft coupling and finite chemical potential. It derives a general metric-based formula for $\hat{q}$ applicable to black-brane geometries, then evaluates finite coupling corrections via $\alpha'$-induced deformations of the D3-brane background, finding a mild suppression that suggests a smooth interpolation toward perturbative results. It also analyzes the impact of a chemical potential for the $U(1)^3$ R-symmetry by studying the rotating D3-brane background, showing that $\hat{q}$ increases with charges within thermodynamic stability, and provides canonical/grand-canonical expansions to connect holographic results with field theory parameters. Together, these results offer holographic predictions for jet quenching across coupling and chemical potential, and hint at finite-mass extensions for more realistic quark probes.

Abstract

Following the nonperturbative prescription for the jet quenching parameter recently proposed by Liu, Rajagopal and Wiedemann, we compute the first correction in the inverse `t Hooft coupling corresponding to string alpha' corrections in the dual background. We also consider the introduction of a chemical potential for the U(1)^3 gauged R-symmetry. While the former mildly diminishes the jet quenching parameter -this suggesting a smooth interpolation between the strong coupling and perturbative results-, the latter generically increases its value. We comment on the extension of this setup to quarks of finite mass.