Gauge invariant definition of the jet quenching parameter
2013; Springer Nature; Volume: 2013; Issue: 2 Linguagem: Inglês
10.1007/jhep02(2013)129
ISSN1127-2236
AutoresMichael Benzke, Nora Brambilla, Miguel Ángel Escobedo, Antonio Vairo,
Tópico(s)Particle physics theoretical and experimental studies
ResumoIn the framework of Soft-Collinear Effective Theory, the jet quenching parameter, $\hat{q}$, has been evaluated by adding the effect of Glauber gluon interactions to the propagation of a highly-energetic collinear parton in a medium. The result, which holds in covariant gauges, has been expressed in terms of the expectation value of two Wilson lines stretching along the direction of the four-momentum of the parton. In this paper, we show how that expression can be generalized to an arbitrary gauge by the addition of transverse Wilson lines. The transverse Wilson lines are explicitly computed by resumming interactions of the parton with Glauber gluons that appear only in non-covariant gauges. As an application of our result, we discuss the contribution to $\hat{q}$ coming from transverse momenta of order $g^2T$ in a medium that is a weakly-coupled quark-gluon plasma.
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