Measurement of the t distribution
diffractive photoproduction at HERA
The ZEUS Collaboration, J. Breitweg et al.
Argonne National Laboratory, Argonne, IL, USA
Received: 3 December 1997
Photon diffractive dissociation, , has been studied at HERA with the ZEUS detector using ep interactions where the virtuality Q2 of the exchanged photon is smaller than 0.02 GeV2. The squared four-momentum t exchanged at the proton vertex was determined in the range 0.073<|t|<0.40 GeV2 by measuring the scattered proton in the ZEUS Leading Proton Spectrometer. In the photon-proton centre-of-mass energy interval 176<W<225 GeV and for masses of the dissociated photon system 4<MX<32 GeV, the t distribution has an exponential shape, , with a slope parameter (stat.) +1.2-1.1 (syst.) GeV-2.