Medium-induced color flow softens hadronization
Abstract
Medium-induced parton energy loss, resulting from gluon exchanges between the QCD matter and partonic projectiles, is expected to underly the strong suppression of jets and high- hadron spectra observed in ultra-relativistic heavy ion collisions. Here, we present the first color-differential calculation of parton energy loss. We find that color exchange between medium and projectile enhances the invariant mass of energetic color singlet clusters in the parton shower by a parametrically large factor proportional to the square root of the projectile energy. This effect is seen in more than half of the most energetic color-singlet fragments of medium-modified parton branchings. Applying a standard cluster hadronization model, we find that it leads to a characteristic additional softening of hadronic spectra. A fair description of the nuclear modification factor measured at the LHC may then be obtained for relatively low momentum transfers from the medium.
Cite
@article{arxiv.1109.5025,
title = {Medium-induced color flow softens hadronization},
author = {A. Beraudo and J. G. Milhano and U. A. Wiedemann},
journal= {arXiv preprint arXiv:1109.5025},
year = {2015}
}