Measurement of Neutral and Charged Current Cross-Sections in Positron-Proton Collisions at Large Momentum Transfer

TL;DR

This paper reports measurements of neutral and charged current cross-sections in positron-proton collisions at high momentum transfer, testing proton structure and electroweak effects consistent with the Standard Model.

Contribution

It provides new measurements of cross-sections and parton distributions at high Q^2, and observes electroweak effects in line with theoretical predictions.

Findings

No significant deviation from perturbative QCD predictions.

Determined the proton structure function F_2(x,Q^2).

Observed electroweak effects consistent with the Standard Model.

Abstract

The inclusive single and double differential cross-sections for neutral and charged current processes with four-momentum transfer squared Q^2 between 150 and 30,000 GeV2 and with Bjorken x between 0.0032 and 0.65 are measured in e^+ p collisions. The data were taken with the H1 detector at HERA between 1994 and 1997, and they correspond to an integrated luminosity of 35.6 pb^-1. The Q^2 evolution of the parton densities of the proton is tested, yielding no significant deviation from the prediction of perturbative QCD. The proton structure function F_2(x,Q^2) is determined. An extraction of the u and d quark distributions at high x is presented. At high Q^2 electroweak effects of the heavy bosons Z0 and W are observed and found to be consistent with Standard Model expectation.