On model independent extraction of the Kaon Fragmentation Functions

TL;DR

This paper introduces a model-independent method to extract the non-singlet kaon fragmentation functions from various processes, enabling tests of common assumptions and universality without relying on prior models or assumptions.

Contribution

It provides a novel, assumption-free approach to determine the non-singlet kaon fragmentation functions across different processes, applicable at any QCD order.

Findings

Successfully extracted (D_u-D_d)^{K^++K^-} from e+e- data.

Compared results with existing global fit parametrizations.

Method allows testing of universality and common assumptions in fragmentation functions.

Abstract

We present a model independent approach to FFs, which allows to determine uniquely the non-singlet combination (D_u-D_d)^{K^++K^-} of the kaon FFs, independently in the three different processes of kaon inclusive production: e+e- annihilation, pp-collisions and lN semi-inclusive DIS. Only C and SU(2) invariances are used and no assumptions on FFs and PDFs, the result holds in any order in QCD. The non-singlets obtained in this way, would allow to test the commonly used assumptions in global fit analysis and to test universality. This method is applied to kaon production data in e+e-\to K+X,\,K=K^\pm, K^0_s and (D_u-D_d)^{K^++K^-} is obtained without any assumptions. This result is compared to the existing parametrizations, obtained in global fit analysis.