Measurement of the hadronic photon structure function F2γ at LEP2

The hadronic structure of the photon F2gamma is measured as a function of Bjorken x and of the photon virtuality Q2 using deep-inelastic scattering data taken by the OPAL detector at LEP at e+e- centre-of-mass energies from 183 to 209 GeV. Previous OPAL measurements of the x dependence of F2gamma are extended to an average Q2 of =780GeV2 using data in the kinematic range 0.15 < x < 0.98. The Q2 evolution of F2gamma is studied for 12.1 < < 780GeV2 using three ranges of x. As predicted by QCD, the data show positive scaling violations in F2gamma for the central x region 0.10-0.60. Several parameterisations of F2gamma are in qualitative agreement with the measurements whereas the quark-parton model prediction fails to describe the data. The hadronic structure function of the photon F 2 γ ( x , Q 2 ) is measured as a function of Bjorken x and of the photon virtuality Q 2 using deep-inelastic scattering data taken by the OPAL detector at LEP at e + e − centre-of-mass energies from 183 to 209 GeV. Previous OPAL measurements of the x dependence of F 2 γ are extended to an average Q 2 of 〈 Q 2 〉=780 GeV 2 using data in the kinematic range 0.15< x =780GeV2 using data in the kinematic range 0.15 < x < 0.98. The Q2 evolution of F2gamma is studied for 12.1 < < 780GeV2 using three ranges of x. As predicted by QCD, the data show positive scaling violations in F2gamma for the central x region 0.10-0.60. Several parameterisations of F2gamma are in qualitative agreement with the measurements whereas the quark-parton model prediction fails to describe the data.