Fit of electroweak parameters in polarized deep-inelastic scattering using data from the H1 experiment

Abstract

The vector and axial-vector couplings of light quarks to the \(Z^0\)-boson are determined using the final deep-inelastic \(e^+p\) and \(e^-p\) neutral and charged current scattering cross sections from the H1 experiment at the HERA collider. The fit determines the electroweak parameters together with the parameters of parton distribution functions (PDFs) in order to account for the PDF uncertainties. Compared to an earlier analysis, the precision of the electroweak parameters is improved since the extraction benefits from the data taken with longitudinally polarized electron and positron beams. The work is further extended towards a consistency study of the Standard Model of Particle Physics in the domain of space-like momentum transfer by determining also the masses of the \(Z^0\) and \(W\)-bosons, or by determining the Fermi coupling constant \(G_F\),or the weak mixing angle \sw together with the \(W\)-boson mass. The large kinematic reach of the data is exploited and the weak mixing angle, defined in the on-shell scheme, is determined at various scales in the range of the data of \(12<Q^2<50\,000\GeVsq\). The results are in agreement with the Standard Model expectations or with other measurements.