O(g) plasma effects in jet quenching

TL;DR

This paper investigates how classical plasma physics effects introduce significant O(g) corrections to jet quenching energy loss in quark-gluon plasma, impacting theoretical predictions and suggesting new lattice study approaches.

Contribution

It calculates large O(g) plasma effects on jet quenching rates at weak coupling, incorporating them into the transverse momentum broadening coefficient with a novel effective theory approach.

Findings

O(g) corrections significantly modify jet quenching rates

Corrections can be absorbed into a modified $t{q}$ coefficient

Effective Euclideanization enables potential nonperturbative lattice studies

Abstract

We consider the bremsstrahlung energy loss of high energy partons moving in the quark-gluon plasma, at weak coupling. We show that the rates for these processes receive large O(g) corrections from classical (nonabelian) plasma physics effects, which are calculated. In the high-energy (deep LPM) regime these corrections can be absorbed in a change of the transverse momentum broadening coefficient $\hat{q}$, which we give to the next-to-leading order. The correction is large even at relatively weak couplings $\alpha_s\sim 0.1$, as is typically found for such effects, signaling difficulties with the perturbative expansion. Our approach is based on an effective "Euclideanization" property of classical physics near the light-cone, which allows an effective theory approach based on dimensional reduction and suggests a new possibility for the nonperturbative lattice study of these effects.