FIZIKA B 17 (2008) 2, 339 - 348
CONFRONTING FRAGMENTATION FUNCTION UNIVERSALITY WITH SINGLE HADRON INCLUSIVE
PRODUCTION AT HERA
CARLOS SANDOVAL
Universität Hamburg, II. Institut für Theoretische Physik,
Luruper Chaussee 149, 22761, Hamburg, Germany
Received 23 October 2007; Accepted 20
February 2008
Online 11 July 2008
Predictions for light charged hadron production data in the current
fragmentation region of deeply inelastic scattering from the H1 and ZEUS
experiments are calculated using perturbative QCD at next-to-leading order, and
using fragmentation functions obtained by fitting to similar data from e+e- reactions. Good agreement was obtained with the HERA data from years
1994 to 1997. There is a discrepancy at low Q and small scaled momentum xp,
that was reduced by incorporating mass effects of the detected hadron. We also
studied the contributions from the different hadron species, as well as from the
various quark flavours in the ep reaction by performing quark tagging in the
calculation. Comparisons to more recent and precise data show a larger
discrepancy due to various neglected effects in our calculation, such as quark
masses, soft gluon resummation and higher twist.
PACS numbers: 13.60.Hb, 13.60.-r ,13.65.+i
UDC 539.125
Keywords: charged hadron production, deeply inelastic scattering, H1 and ZEUS
experiments, perturbative QCD
|