Intensity of gluon bremsstrahlung in a finite plasma

Abstract

The intensity of single gluon bremsstrahlung in a QCD plasma is evaluated with a Monte Carlo which solves the transport equation for a generic interaction with the medium. In particular the calculation is performed for a Debye screened potential and compared to the well known Gaussian/Fokker-Planck results. The full calculation including the first and last gluons show a qualitatively different behavior from the BDMPS result for any finite medium length. It is shown that the emission intensity is underestimated for the Gaussian approximation, compared to the Debye screened potential. This change can not be accounted for by a redefinition of the Gaussian parameter (q). * Electronic address: xabier.feal@igfae.usc.es † Electronic address: vazquez@igfae.usc.es where Ψ 1,2 (x) represent the quark wave function before and after the emission, A µ (x) = A µ α (x)t α represents the emitted colored gluon, t α are generators of SU(3) and g s = √ α s is the coupling constant. Both quark and arXiv:1811.01591v1 [hep-ph]

Medium-induced gluon radiation with full resummation of multiple scatterings for realistic parton-medium interactions

“…The numerical evaluation of the path integral in eq. (23) including all the multiple scatterings for a realistic collision rate V (q) -such as a Yukawa-like interaction -has always posed technical problems, which could not be overcome until very recently with advanced Monte Carlo techniques [13]. For this reason, the spectrum in eq.…”

“…This is the case of the harmonic or multiple soft scattering approximation, which assumes a Gaussian profile for the transverse momentum transfers and does not reproduce the perturbative tails at high transverse momentum k ⊥ . Given the impossibility of having fully analytical expressions, numerical implementations would be highly desirable, but so far, the only thorough attempts to numerically evaluate the emission spectrum and its k ⊥ -dependence have been through computationally costly Monte Carlo implementations [13].…”

A complete set of in-medium splitting functions to any order in opacity

“…The possibility of a hard scattering was added to the infinite medium soft scattering soft scattering approximation [21]. Importantly, it was recently shown in the work of Feal and Vasquez [22,23] that analytic approximations to in-medium splitting processes are not a good substitute for their full numerical evaluation.…”

Jet quenching and effects of non-Gaussian transverse-momentum broadening on dijet observables

“…However, transverse momentum exchange between the jet and the medium is also expected. These are manifestations of the quasiparticles of the hot and dense matter and affect both the spectrum of radiated gluons [17][18][19][20][21][22][23] as well as the distribution of particles in transverse momentum space [24,25]. An important question is whether jet observables are sensitive to such interactions, especially those that are sensitive to recoils.…”

“…In order to describe the propagation of partons produced in hard collisions inside a hot quark-gluon plasma, we have applied the recently developed Monte Carlo generator MINCAS [42] that solves the rate equation describing the rescattering and radiation of a hard parton in a dense QCD medium [44] (for a similar approach see Refs. [18,19]).…”