Measurement of high-Q(2) charged-current e(+)p deep inelastic scattering cross sections at HERA

The charged-current deep inelastic scattering cross sections, for between 200 and 60000 GeV, and and for GeV, have been measured with the ZEUS detector at HERA. A data sample of 47.7 pb, collected at a center-of-mass energy of 300 GeV, has been used. The double-differential cross-section falls by a factor of about 50000 as increases from 280 to 30000 GeV. The double differential cross section has also been measured. A comparison between the data and Standard Model (SM) predictions shows that contributions from antiquarks ( and ) and quarks (d ands) are both required by the data. The predictions of the SM give a good description of the full body of the data presented here. A comparison of the charged-current cross-section with the recent ZEUS results for neutral-current scattering shows that the weak and electromagnetic forces have similar strengths for above . A fit to the data for with the Fermi constant and as free parameters yields and . Results for , where the propagator effect alone or the SM constraint between and have been considered, are also presented.