Measurement of Neutral and Charged Current Cross Sections in Electron-Proton Collisions at High Q^2

TL;DR

This paper reports measurements of electron-proton scattering cross sections at high momentum transfer, revealing asymmetries and extracting structure functions and W boson mass, confirming Standard Model predictions.

Contribution

First measurement of the generalized structure function xF_3 at HERA and extraction of the W boson mass from charged current data.

Findings

Evidence of e^+p and e^-p asymmetry at high Q^2

First extraction of xF_3 structure function at HERA

W boson mass consistent with Standard Model

Abstract

The inclusive e^-p single and double differential cross sections for neutral and charged current processes are measured with the H1 detector at HERA, in the range of four-momentum transfer squared Q^2 between 150 and 30000 GeV^2, and Bjorken x between 0.002 and 0.65. The data were taken in 1998 and 1999 with a centre-of-mass energy of 320 GeV and correspond to an integrated luminosity of 16.4 pb^(-1). The data are compared with recent measurements of the inclusive neutral and charged current e^+p cross sections. For Q^2>1000 GeV^2 clear evidence is observed for an asymmetry between e^+p and e^-p neutral current scattering and the generalised structure function xF_3 is extracted for the first time at HERA. A fit to the charged current data is used to extract a value for the W boson propagator mass. The data are found to be in good agreement with Standard Model predictions.