Towards a model independent approach to fragmentation functions

TL;DR

This paper demonstrates a model-independent method to determine specific fragmentation functions in high-energy particle collisions, enabling validation of existing models and Q^2 evolution without relying on assumptions.

Contribution

It introduces a novel approach to extract fragmentation functions independently in any order of QCD, using difference cross sections in SIDIS and pp collisions, reducing reliance on models.

Findings

Determines D_u^{h-ar h} and D_d^{h-ar h} independently from experimental data.

Provides a way to test existing fragmentation function parametrizations.

Enables validation of Q^2 evolution and factorization assumptions.

Abstract

We show that the difference cross sections in unpolarized SIDIS e+N\to e+h+X and pp hadron production p+p\to h+X determine independently in a model independent way, in any order in QCD, the two FFs: D_u^{h-\bar h} and D_d^{h-\bar h}, h=\pi^\pm, K^\pm or a sum over charged hadrons. If both K^\pm and K_s^0 are measured, then e+e-\toK+X, e+N\to e+K+X and p+p\to K+X present independent measurements of just one FF: D_{u-d}^{K^++K^-}. The above results allow to test the existing parametrizations, obtained with various different assumptions about the FFs, and to test the $Q^2$ evolution and factorization.