Measurement of Diffractive Scattering of Photons with Large Momentum Transfer at HERA

Abstract

The first measurement of diffractive scattering of quasi-real photons with large momentum transfer is made using the H1 detector at HERA. Single differential cross sections are measured as a function of W, the incident photon-proton centre of mass energy, and t, the square of the four-momentum transferred at the proton vertex. The W dependence is well described by a perturbative QCD model using a leading logarithmic approximation of the BFKL evolution, whereas the measured |t| dependence is harder than predicted.