Eur. Phys. J. C 18, 625-637
DOI: 10.1007/s100520100571
Measurement of open beauty production in photoproduction at HERA
The ZEUS Collaboration J. Breitweg and et al.Argonne National Laboratory, Argonne, IL, USA
(Received: 22 November 2000 / Published online: 5 February 2001 -© Springer-Verlag 2001)
Abstract
The production and semi-leptonic decay of heavy quarks have been studied in the
photoproduction process
with the ZEUS
detector at HERA using an integrated luminosity of 38.5
. Events with
photon-proton centre-of-mass energies,
, between 134 and 269 GeV and a
photon virtuality, Q2, less than 1
were selected requiring at least two
jets of transverse energy
GeV and an electron in the final
state. The electrons were identified by employing the ionisation energy loss
measurement.
The contribution of beauty quarks was determined using the transverse
momentum of the
electron relative to the axis of the closest jet,
. The data, after
background subtraction, were fit
with a Monte Carlo simulation including beauty and charm decays. The measured beauty
cross section was extrapolated to the parton level with the b quark restricted to the
region of transverse momentum
5 GeV and pseudorapidity
2. The extrapolated cross section is
. The result
is compared to a perturbative QCD calculation performed to next-to-leading
order.
© Società Italiana di Fisica, Springer-Verlag 2001