Medium-evolved fragmentation functions
Abstract
Medium-induced gluon radiation is usually identified as the dominant dynamical mechanism underling the {\it jet quenching} phenomenon observed in heavy-ion collisions. In its actual implementation, multiple medium-induced gluon emissions are assumed to be independent, leading, in the eikonal approximation, to a Poisson distribution. Here, we introduce a medium term in the splitting probabilities so that both medium and vacuum contributions are included on the same footing in a DGLAP approach. The improvements include energy-momentum conservation at each individual splitting, medium-modified virtuality evolution and a coherent implementation of vacuum and medium splitting probabilities. Noticeably, the usual formalism is recovered when the virtuality and the energy of the parton are very large. This leads to a similar description of the suppression observed in heavy-ion collisions with values of the transport coefficient of the same order as those obtained using the {\it quenching weights}.
Cite
@article{arxiv.0710.3073,
title = {Medium-evolved fragmentation functions},
author = {N. Armesto and L. Cunqueiro and C. A. Salgado and W. -C. Xiang},
journal= {arXiv preprint arXiv:0710.3073},
year = {2010}
}
Comments
LaTeX, 18 pages, 13 figures included using epsfig, uses JHEP3; v2: enlarged discussions, one figure replaced, some references added, final version