First QCD analysis of charged hadron fragmentation functions and their uncertainties at next-to-next-to-leading order

In this paper, we present SGK18 FFs, a first QCD analysis of Parton-to- unidentified charged hadrons fragmentation functions (FFs) at next-to-next-to-leading order (NNLO) accuracy in perturbative QCD. This analysis is based on single-inclusive charged hadron production in electron-positron (e−eþ) annihilation. The uncertainties in the extraction of SGK18 FFs as well as the corresponding observables are estimated using the “Hessian” technique. We study the quality of the SGK18 FFs determined in this analysis by comparing them with the recent results in the literature.We also show how SGK18 FFs results describe the available data for single-inclusive unidentified charged hadron production in e−eþ annihilation. We demonstrate that the theoretical uncertainties due to the variation of the renormalization and factorization scales improve when NNLO QCD corrections are considered. We find that the resulting SGK18 FFs are in good agreement with all data analyzed and the inclusion of NNLO corrections tends to improve the data description with somewhat smaller uncertainty