Measurement of the forward-backward charge asymmetry and extraction of sin^2Theta^{eff}_W in ppbar -> Z/\gamma^{*}+X -> e+e+X events produced at \sqrt{s}=1.96 TeV

TL;DR

This paper measures the forward-backward charge asymmetry in proton-antiproton collisions producing Z/gamma* to electron-positron pairs at 1.96 TeV, and uses it to determine the effective weak mixing angle, testing the Standard Model predictions.

Contribution

First measurement of $A_{FB}$ as a function of invariant mass at Tevatron energies, leading to a new extraction of $sin^2Theta^{eff}_W$ with improved precision.

Findings

$A_{FB}$ is consistent with the Standard Model.

Extracted $sin^2Theta^{eff}_W = 0.2327 \, ext{with uncertainties}$.

Provides constraints on electroweak parameters.

Abstract

We present a measurement of the forward-backward charge asymmetry ($A_{FB}$) in $p\bar{p} \to Z/\gamma^{*}+X \to e^+e^-+X$ events at a center-of-mass energy of 1.96 TeV using 1.1 fb$^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron collider. $A_{FB}$ is measured as a function of the invariant mass of the electron-positron pair, and found to be consistent with the standard model prediction. We use the $A_{FB}$ measurement to extract the effective weak mixing angle $sin^2Theta^{eff}_W = 0.2327 \pm 0.0018 (stat.) \pm 0.0006 (syst.)$.