A measurement of the Q2, W and t dependences of deeply virtual Compton scattering at HERA

Abstract

Deeply virtual Compton scattering, γ*p → γp, has been measured in e+p collisions at HERA with the ZEUS detector using an integrated luminosity of 61.1 pb−1. Cross sections are presented as a function of the photon virtuality, Q2, and photon-proton centre-of-mass energy, W, for a wide region of the phase space, Q2 > 1.5 GeV2 and 40 <W <170 GeV. A subsample of events in which the scattered proton is measured in the leading proton spectrometer, corresponding to an integrated luminosity of 31.3 pb−1, is used for the first direct measurement of the differential cross section as a function of t, where t is the square of the four-momentum transfer at the proton vertex.