Measurement of neutral and charged current cross-sections in positron-proton collisions at large momentum transfer

Abstract. The inclusive single and double differential cross-sections for neutral and charged current processes with four-momentum transfer squared $$Q^2$$ between 150 and 30 000 GeV$$^2$$ and with Bjorken x between 0.0032 and 0.65 are measured in $$e^+ p$$ collisions. The data were taken with the H1 detector at HERA between 1994 and 1997, and they correspond to an integrated luminosity of $$35.6\,{\rm pb}^{-1}$$. The $$Q^2$$ evolution of the parton densities of the proton is tested, yielding no significant deviation from the prediction of perturbative QCD. The proton structure function $$F_2(x,Q^2)$$ is determined. An extraction of the u and d quark distributions at high x is presented. At high $$Q^2$$ electroweak effects of the heavy bosons $$Z^\circ$$ and $$W$$ are observed and found to be consistent with Standard Model expectation.