Kaon fragmentation function from NJL-jet model

TL;DR

This paper extends the NJL-jet model to include strange quarks, calculating kaon fragmentation functions that qualitatively agree with empirical data, aiding semi-inclusive data analysis.

Contribution

The study introduces strange quarks into the NJL-jet model, providing new calculations of kaon fragmentation functions within an effective chiral quark framework.

Findings

Kaon fragmentation functions qualitatively match empirical parameterizations.

Unfavored strange quark fragmentation to pions is comparable to light quark fragmentation.

Model extension offers guidance for semi-inclusive data analysis.

Abstract

The NJL-jet model provides a sound framework for calculating the fragmentation func- tions in an effective chiral quark theory, where the momentum and isospin sum rules are satisfied without the introduction of ad hoc parameters [1]. Earlier studies of the pion fragmentation func- tions using the Nambu-Jona-Lasinio (NJL) model within this framework showed good qualitative agreement with the empirical parameterizations. Here we extend the NJL-jet model by including the strange quark. The corrections to the pion fragmentation function and corresponding kaon fragmen- tation functions are calculated using the elementary quark to quark-meson fragmentation functions from NJL. The results for the kaon fragmentation function exhibit a qualitative agreement with the empirical parameterizations, while the unfavored strange quark fragmentation to pions is shown to be of the same order of magnitude as the unfavored light quark's. The results of these studies are expected to provide important guidance for the analysis of a large variety of semi-inclusive data.