Photoproduction of large-mass lepton pairs at HERA as a probe of the small $x$ structure of the proton

A. C. Bawa, K. Charchula, W. J. Stirling

The photoproduction of Drell-Yan lepton pairs at HERA is studied. We show that in the backward rapidity region the cross section is strongly sensitive to the small-$x$ behaviour of…