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

The \(e^+p\) charged-current deep inelastic scattering cross sections, \(d\sigma/dQ^2\) for \(Q^2\) between 200 and 60000 GeV\(^2\), and \(d\sigma/dx\) and \(d\sigma/dy\) for \(Q^2 > 200\) GeV\(^2\), have been measured with the ZEUS detector at HERA. A data sample of 47.7 pb\(^{-1}\), collected at a center-of-mass energy of 300 GeV, has been used. The double-differential cross-section \(d\sigma/dQ^2\) falls by a factor of about 50000 as \(Q^2\) increases from 280 to 30000 GeV\(^2\). The double differential cross section \(d^2\sigma/dxdQ^2\) has also been measured. A comparison between the data and Standard Model (SM) predictions shows that contributions from antiquarks (\(\overlineu\) and \(\overline c\)) 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 \(d\sigma/dQ^2\) with the recent ZEUS results for neutral-current scattering shows that the weak and electromagnetic forces have similar strengths for \(Q^2\) above \(M^2_W, M^2_Z\). A fit to the data for \(d\sigma/dQ^2\) with the Fermi constant \(G_F\) and \(M_W\) as free parameters yields \(G_F = \left( 1.171 {\pm 0.034} \,{\rm (stat.)} ^{+0.026}_{-0.032} \,{\rm (syst.)} ^{+0.016}_{-0.015} \,{\rm (PDF)} \right)\times10^{-5}\,{\rm GeV^{-2}}\) and \(M_W = 80.8 ^{+4.9}_{-4.5} \,{\rm (stat.)} ^{+5.0}_{-4.3} \,{\rm (syst.)} ^{+1.4}_{-1.3} \,{\rm (PDF) GeV}\). Results for \(M_W\), where the propagator effect alone or the SM constraint between \(G_F\) and \(M_W\) have been considered, are also presented.