
Yacine MehtarTani, Carlos A. Salgado, Konrad Tywoniuk
The radiation pattern of a QCD antenna in a dilute medium
Abstract
Radiative interferences in the multiparton shower is the building block of QCD jet physics in vacuum. The presence of a hot medium made of quarks and gluons is expected to alter this interference pattern. To study these effects, we derive the gluon emission spectrum off a colorcorrelated quarkantiquark pair (antenna) traversing a colored medium to first order in the medium density. The resulting induced gluon distribution is found to be governed by the hardest scale of the problem. In our setup, this can either be the inverse antenna transverse size, $r_\perp^{1}$, or the scale related to the transverse color correlation length in the medium, which is given by the Debye mass $m_D$. This emerging scale opens the angular phase space of emissions off the antenna compared to the vacuum case and gives rise to a typical transverse momentum of the mediuminduced emitted gluons, $_{\text{med}}\sim \text{max}(r_\perp^{1},m_D)$. Above the hard scale interference effects suppress the spectrum resulting in the restoration of vacuum coherence.
LU TP 1118
