Single photoproduction of neutral π-mesons on hydrogen in the forward direction at 4 GeV

The differential cross section of the reaction γp → π0p has been measured at the Deutsches Elektronen Synchrotron DESY, Hamburg, at a mean photon energy of 4.0 GeV in the four-momentum transfer range between t = −0.2 (GeV/c)2 and t = −1,2 (GeV/c)2 in steps of approximately 0.08 (GeV/c)2. The experiment was carried out in connection with the measurements of the photoproduction of π0 mesons on deuterium, which were described in the preceding article. In the present paper the contributions arising from background reactions are discussed in more detail.