Medium-modified DGLAP evolution of fragmentation functions from large to small x

TL;DR

This paper extends the DGLAP evolution framework for fragmentation functions to include medium effects, accounting for soft gluon logarithms, and aligns well with experimental observations of hadron production.

Contribution

It introduces a generalized medium-modified DGLAP evolution approach that incorporates double logarithms and matches experimental data without additional assumptions.

Findings

Suppressed high-momentum hadron production in medium

Enhanced soft hadron production at small momenta

More comprehensive than previous medium evolution models

Abstract

The unified description of fragmentation function evolution from large to small x which was developed for the vacuum in previous publications is now generalized to the medium, and is studied for the case in which the complete contribution from the largest class of soft gluon logarithms, the double logarithms, are accounted for and with the fixed order part calculated to leading order. In this approach it proves possible to choose the remaining degrees of freedom related to the medium such that the distribution of produced hadrons is suppressed at large momenta while the production of soft radiation-induced charged hadrons at small momenta is enhanced, in agreement with experiment. Just as for the vacuum, our approach does not require further assumptions concerning fragmentation and is more complete than previous computations of evolution in the medium.