Jet energy loss in the quark-gluon plasma by stream instabilities

TL;DR

This paper investigates how jets of particles induce plasma instabilities in a quark-gluon plasma, leading to energy transfer through unstable gauge fields and hard modes, using numerical simulations and analytical models.

Contribution

It introduces a combined numerical and analytical study of jet-induced instabilities and energy loss mechanisms in a non-Abelian plasma with simplified jet distributions.

Findings

Jets excite unstable chromomagnetic and chromoelectric modes.

Energy is absorbed by gauge fields and plasma hard modes.

Numerical and analytical results show qualitative agreement.

Abstract

We study the evolution of the plasma instabilities induced by two jets of particles propagating in opposite directions and crossing a thermally equilibrated non-Abelian plasma. In order to simplify the analysis we assume that the two jets of partons can be described with uniform distribution functions in coordinate space and by Gaussian distribution functions in momentum space. We find that while crossing the quark-gluon plasma, the jets of particles excite unstable chromomagnetic and chromoelectric modes. These fields interact with the particles (or hard modes) of the plasma inducing the production of currents; thus, the energy lost by the jets is absorbed by both the gauge fields and the hard modes of the plasma. We compare the outcome of the numerical simulations with the analytical calculation performed assuming that the jets of particles can be described by a tsunami-like distribution function. We find qualitative and semi-quantitative agreement between the results obtained with the two methods.