Charged particles and neutral kaons in photoproduced jets at HERA
ZEUS Collaboration, J. Breitweg et al.
Argonne National Laboratory, Argonne, IL, USA
Received: 18 November 1997
Abstract
Charged particles (
) and K0 mesons have been studied in
photoproduced events containing at least one jet of ET > 8GeV
in a pseudorapidity interval (-0.5, 0.5) in the ZEUS laboratory frame.
Distributions are presented in terms of transverse momentum, pseudorapidity
and distance of the particle from the axis of a jet. The properties
of within the jet are described well using the standard
settings of PYTHIA, but the use of the multiparton interaction option
improves the description outside the jets. A reasonable overall
description of the K0 behaviour is possible with PYTHIA using
a reduced value of the strangeness suppression parameter.
The numbers of and K0 within a jet as defined above are measured to be
and 
respectively.
Fragmentation functions are presented for and K0 in
photoproduced jets; agreement is found with calculations of
Binnewies et al. and, at higher momenta, with
scattering and with standard PYTHIA.
Fragmentation functions in direct photoproduced events are extracted, and
at higher momenta give good agreement with data from related processes
in e+e- annihilation and deep inelastic ep scattering.
Copyright Springer-Verlag
