Fragmentations Functions in Nuclear Media

TL;DR

This paper analyzes how hadronization in nuclear media can be modeled using effective fragmentation functions, which are extracted from experimental data and show significant differences from standard functions, supporting factorization and universality.

Contribution

It introduces a phenomenological approach to describe medium-modified fragmentation functions and provides NLO-accurate sets fitted to experimental data, demonstrating their distinct shape and magnitude.

Findings

Effective fragmentation functions differ significantly from standard ones.

The approach accurately describes semi-inclusive DIS and hadron production data.

Results support the factorization and universality hypotheses in nuclear environments.

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.