Determination of the fragmentation functions from an NLO QCD analysis of the HERMES data on pion multiplicities

TL;DR

This paper performs an NLO QCD analysis of HERMES pion multiplicity data to extract new pion fragmentation functions, highlighting discrepancies between different data presentations.

Contribution

It introduces a new set of pion fragmentation functions derived from an NLO QCD fit to HERMES data, addressing presentation inconsistencies.

Findings

Successful fit to [Q^2,z] data presentation

Identification of issues with [x,z] data presentation

New pion fragmentation functions extracted

Abstract

An NLO QCD analysis of the final HERMES data on pion multiplicities is presented and a new set of pion fragmentation functions is extracted from the best fit to the data. We have studied the so-called [x,z] and [Q^2,z] presentations of their data, as given by HERMES, which, in principle, should simply be two different ways of presenting the experimental data. We have based our extraction on an excellent fit to the [Q^2,z] presentation of the data. We also draw attention to what appears to be a problem with the [x,z] presentation of the HERMES data.