Measurement of the photon-proton total cross section at a center-of-mass energy of 209 GeV at HERA
arXiv:hep-ex/0202034 · doi:10.1016/S0550-3213(02)00068-8
Abstract
The photon-proton total cross section has been measured in the process e+ p -> e+ gamma p -> e+ X with the ZEUS detector at HERA. Events were collected with photon virtuality Q^2 < 0.02 GeV^2 and average gamma-p center-of-mass energy W_{gamma p} = 209 GeV in a dedicated run, designed to control systematic effects, with an integrated luminosity of 49 nb^{-1}. The measured total cross section is sigma_{tot}^{gamma p} = 174 +- 1 (stat.) +- 13 (syst.) microbarns. The energy dependence of the cross section is compatible with parameterizations of high-energy p-p and p-pbar data.
21 pages, 8 figures, accepted by Nuclear Physics B