Measurement of the $Q^{2}$ dependence of the Charged and Neutral Current Cross Sections in $e^{\pm}p$ Scattering at HERA

TL;DR

This paper measures how the cross sections for charged and neutral current processes in electron-proton scattering depend on the momentum transfer squared ($Q^2$) at HERA, revealing comparable cross sections at high $Q^2$ and estimating the W boson mass.

Contribution

It provides the first detailed measurement of $Q^2$ dependence of charged and neutral current cross sections at high energies and determines the W boson mass from these data.

Findings

Neutral and charged current cross sections are comparable above $Q^2 \,\approx\, 5000$ GeV$^2$.

The W boson propagator mass is estimated as $84^{+10}_{-7}$ GeV.

Cross section measurements agree with Standard Model predictions.

Abstract

The $Q^{2}$ dependence and the total cross sections for charged and neutral current processes are measured in $e^{\pm}p$ reactions for transverse momenta of the outgoing lepton larger than 25 GeV. Comparable size of cross sections for the neutral current process and for the weak charged current process are observed above $Q^2~\approx~5000$ GeV$^2$. Using the shape and magnitude of the charged current cross section we determine a propagator mass of $m_{W} = 84\ ^{+10}_{-7}$ GeV.