Medium-induced gluon radiation beyond the eikonal approximation

TL;DR

This paper advances the theoretical understanding of medium-induced gluon radiation by incorporating energy-momentum conservation and transverse motion in the calculations, extending previous models to all energy fractions and arbitrary formation times.

Contribution

It introduces a comprehensive path-integral formalism that accounts for energy-momentum conservation and transverse dynamics in in-medium gluon emissions across all momentum fractions.

Findings

Extended the gluon radiation model to all x values.

Included transverse motion of all particles in the emission process.

Provided general expressions within the harmonic oscillator approximation.

Abstract

In this work we improve existing calculations of radiative energy loss by computing corrections that implement energy-momentum conservation, previously only implemented a posteriori, in a rigorous way. Using the path-integral formalism, we compute in-medium splittings allowing transverse motion of all particles in the emission process, thus relaxing the assumption that only the softest particle is permitted such movement. This work constitutes the extension of the computation carried out for x$\rightarrow$1 in Phys. Lett. B718 (2012) 160-168, to all values of x, the momentum fraction of the energy of the parent parton carried by the emitted gluon. In order to accomplish a general description of the whole in-medium showering process, in this work we allow for arbitrary formation times for the emitted gluon. We provide general expressions and their realisation in the path integral formalism within the harmonic oscillator approximation.