Measurement of the inclusive dijet cross-section in photoproduction and determination of an effective parton distribution in the photon

DESY-HERA. Measurement of the inclusive 2-JET cross section in photoproduction and determination of an Effective Parton Distribution in the photon. Integrated luminocity used for this analysis is 2.9 1/pb. Data were taken in 1994. & apos;The photoproduction events were selected by requiring that the scattered electron remains in the beam pipe (untagged events), therefore photon virtuality Q2& lt;4 GeV2, where 80 PCT of the events have Q2& lt;0.1 GeV2& apos;. X(C=GAMMA) = (E(jet1)*EXP(-ETARAP(jet1))+E(jet2)*EXP(-ETARAP(jet2) ))/ (2*Y*E_e) is the fraction of quasi-real photon momentum carried by its parton, where Y is the fraction of the lepton beam energy carried by quasi-real photon: Y = E_gamma/E_e. ET is in GeV.