Fragmentations Functions in Nuclear Media
Rodolfo Sassot, Marco Stratmann, Pia Zurita
TL;DR
The study investigates whether hadronization in nuclear environments can be described by medium-modified fragmentation functions that factorize from hard scattering and evolve like vacuum FFs. It introduces a convolution framework where nFFs are generated from vacuum FFs through nuclear weight functions, and performs a global NLO analysis of SIDIS off nuclei and dAu data to extract pion and kaon nFFs. The fit reveals quark fragmentation is suppressed while gluon fragmentation is enhanced in nuclei, with a coherent A-dependence and good data description, supporting factorization and universality of nFFs within current precision. The approach provides a data-driven baseline for interpreting hadronization in more extreme nuclear systems and informs heavy-ion phenomenology by quantifying medium effects on final-state hadrons.
Abstract
We perform a detailed phenomenological analysis of how well hadronization in nuclear environments can be described in terms of effective fragmentation functions. The medium modified fragmentation functions are assumed to factorize from the partonic scattering cross sections and evolve in the hard scale in the same way as the standard or vacuum fragmentation functions. Based on precise data on semi-inclusive deep-inelastic scattering off nuclei and hadron production in deuteron-gold collisions, we extract sets of effective fragmentation functions for pions and kaons at NLO accuracy. The obtained sets provide a rather accurate description of the kinematical dependence of the analyzed cross sections and are found to differ significantly from standard fragmentation functions both in shape and magnitude. Our results support the notion of factorization and universality in the studied nuclear environments, at least in an effective way and within the precision of the available data.