2021 Impact factor 4.991
Particles and Fields
Eur. Phys. J. C 5, 439-452
DOI 10.1007/s100529800963

Multiplicity structure of the hadronic final state
in diffractive deep-inelastic scattering at HERA

H1 Collaboration
C.Adloff34 - et al.

34 Fachbereich Physik, Bergische Universität Gesamthochschule Wuppertal, Wuppertal, Germany

Received: 27 April 1998 / Published online: 3 September 1998

The multiplicity structure of the hadronic system X produced in deep-inelastic processes at HERA of the type $ep
 \rightarrow eXY$, where Y is a hadronic system with mass MY< 1.6 GeV and where the squared momentum transfer at the pY vertex, t, is limited to $\vert t\vert<1\,{\rm GeV}^2$, is studied as a function of the invariant mass MX of the system X. Results are presented on multiplicity distributions and multiplicity moments, rapidity spectra and forward-backward correlations in the centre-of-mass system of X. The data are compared to results in e+e- annihilation, fixed-target lepton-nucleon collisions, hadro-produced diffractive final states and to non-diffractive hadron-hadron collisions. The comparison suggests a production mechanism of virtual photon dissociation which involves a mixture of partonic states and a significant gluon content. The data are well described by a model, based on a QCD-Regge analysis of the diffractive structure function, which assumes a large hard gluonic component of the colourless exchange at low Q2. A model with soft colour interactions is also successful.

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