Measurement of jet shapes in photoproduction at HERA
ZEUS Collaboration, J. Breitweg et al.
Argonne National Laboratory, Argonne, IL, USA
Received: 30 September 1997
Abstract
The shape of jets produced in quasi-real photon-proton collisions at
centre-of-mass energies in the range 134-277 GeV has been measured
using the hadronic energy flow. The measurement was done with the
ZEUS detector at HERA. Jets are identified using a cone algorithm in the
plane with a cone radius of one unit. Measured jet shapes both
in inclusive jet and dijet production with transverse energies
EjetT>14 GeV are presented. The jet shape broadens as the jet
pseudorapidity (
) increases and narrows as EjetT increases.
In dijet photoproduction, the jet shapes have been measured separately for
samples dominated by resolved and by direct processes. Leading-logarithm
parton-shower Monte Carlo calculations of resolved and direct processes
describe well the measured jet shapes except for the inclusive production of
jets with high and low EjetT. The observed broadening of
the jet shape as increases is consistent with the predicted
increase in the fraction of final state gluon jets.
Copyright Springer-Verlag
