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arXiv · hep-ex/9501011

Observation of hard scattering in photoproduction events with a large rapidity gap at HERA

ZEUS Collaboration
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Abstract

Events with a large rapidity gap and total transverse energy greater than 5 GeV have been observed in quasi-real photoproduction at HERA with the ZEUS detector. The distribution of these events as a function of the $γp$ centre of mass energy is consistent with diffractive scattering. For total transverse energies above 12 GeV, the hadronic final states show predominantly a two-jet structure with each jet having a transverse energy greater than 4 GeV. For the two-jet events, little energy flow is found outside the jets. This observation is consistent with the hard scattering of a quasi-real photon with a colourless object in the proton.

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ZEUS Collaboration. 1995-01-25. Observation of hard scattering in photoproduction events with a large rapidity gap at HERA. https://doi.org/10.1016/0370-2693(95)00022-d

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