On the use of running $\alpha_s$ in calculations of radiative energy loss of fast partons in a quark-gluon plasma

TL;DR

This paper discusses how using a running coupling constant _s_s with a specific virtuality scale affects calculations of radiative energy loss of fast partons in a quark-gluon plasma, proposing a more accurate scale choice.

Contribution

It introduces a new perspective on the virtuality scale for _s in gluon emission, emphasizing the transverse momentum squared rather than the invariant mass squared.

Findings

The virtuality scale for _s is better represented by the transverse momentum squared.

This approach impacts the accuracy of radiative energy loss calculations.

The proposed scale choice aligns with physical intuition about gluon emission processes.

Abstract

The incorporation of running $\alpha_s$ for the gluon emission vertex in calculations of radiative parton energy loss in a quark-gluon plasma is discussed. It is argued that the virtuality scale for running $\alpha_s$ for induced gluon emission is determined by the square of the transverse momentum of the emitted gluon rather than by the square of the invariant mass of the final two-parton state often used in the literature.