Measurements of the neutral current cross sections for deep inelastic scattering in e(-) p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections d sigma/dQ(2), d sigma/dx and d sigma/dy and the double-differential cross sections in Q(2) and x are measured in the kinematic region y < 0.9 and Q(2) > 185GeV(2) for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9pb(-1) taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions x (F) over tilde (3) and xF(3)(gamma Z) are determined by combining the e(-) p results presented in this paper with previously measured e(+) p neutral current data. The asymmetry parameter A(-) is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model.
Measurement of high-Q(2) neutral current deep inelastic e(-) p scattering cross sections with a longitudinally polarised electron beam at HERA
A. Longhin;BRUGNERA, RICCARDO;CARLIN, ROBERTO;GARFAGNINI, ALBERTO;
2009
Abstract
Measurements of the neutral current cross sections for deep inelastic scattering in e(-) p collisions at HERA with a longitudinally polarised electron beam are presented. The single-differential cross-sections d sigma/dQ(2), d sigma/dx and d sigma/dy and the double-differential cross sections in Q(2) and x are measured in the kinematic region y < 0.9 and Q(2) > 185GeV(2) for both positively and negatively polarised electron beams and for each polarisation state separately. The measurements are based on an integrated luminosity of 169.9pb(-1) taken with the ZEUS detector in 2005 and 2006 at a centre-of-mass energy of 318 GeV. The structure functions x (F) over tilde (3) and xF(3)(gamma Z) are determined by combining the e(-) p results presented in this paper with previously measured e(+) p neutral current data. The asymmetry parameter A(-) is used to demonstrate the parity violating effects of electroweak interactions at large spacelike photon virtuality. The measurements agree well with the predictions of the Standard Model.Pubblicazioni consigliate
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