Measurement of the Proton Structure from high-<em>Q</em>²</nobr> Neutral Current Events in e⁺p</nobr> Deep Inelastic Scatering at HERA

Abstract

Inclusive Neutral Current cross sections in e⁺p deep inelastic scattering yielding the generalised structure function F₂ have been measured in the regime of Q²>185 GeV². The data sample of 63.2 pb^-1 was collected in the 1999/2000 data-taking period of the ZEUS experiment at the HERA collider. The centre-of-mass energy was sqrt(s)=318 GeV. Statistical and systematic uncertainties have been calculated throughout the kinematical range of the data. Systematic uncertainties were studied including photoproduction background, first-level trigger efficiency and the hadronic final state in the Forward Tracking Devices of the detector. The structure function F₂ was measured more precisely than in earlier measurements due to the larger data set and due to increased knowledge about systematic effects. The results are in good agreement with the Standard Model evaluated with the CTEQ5D parton distribution functions.