Towards a model independent determination of fragmentation functions

TL;DR

This paper demonstrates that certain cross section measurements in SIDIS and proton-proton collisions can uniquely determine specific fragmentation functions, providing a model-independent approach to understanding hadronization processes.

Contribution

It introduces a method to determine fragmentation functions D_u^{h-ar h} and D_d^{h-ar h} directly from experimental data without relying on model assumptions.

Findings

Unique determination of D_u^{h-ar h} and D_d^{h-ar h} from cross section differences.

Validation of the method through comparison with conventional parametrizations.

Potential for independent measurements of (D_u-D_d)^{K^+ +K^-} from multiple processes.

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, uniquely and in any order in QCD, the two FFs: D_u^{h-\bar h} and D_d^{h-\bar h}, h=\pi^\pm, K^\pm. If both K^\pm and K_s^0 are measured, then e+e-\to K+X, e+N\to e+K+X and p+p\to K+X yield independent measurements of (D_u-D_d)^{K^+ +K^-}. In a combined fit to K^\pm and K^0_s production data from e+e- collisions, (D_u-D_d)^{K^++K^-} is obtained and compared to conventional parametrizations.