Measurement of the Electron Charge Asymmetry in $p\overline{p}\to W+X\to e\nu +X$ Events at $\sqrt{s}=1.96\mathrm{TeV}$

We present a measurement of the electron charge asymmetry in $p\overline{p}\to W+X\to e\nu +X$ events at a center of mass energy of 1.96 TeV using $0.75{\mathrm{fb}}^{-1}$ of data collected with the D0 detector at the Fermilab Tevatron Collider. The asymmetry is measured as a function of the electron transverse momentum and pseudorapidity in the interval ($-3.2$, 3.2) and is compared with expectations from next-to-leading order calculations in perturbative quantum chromodynamics. These measurements will allow more accurate determinations of the proton parton distribution functions.

Figure 1

The folded electron charge asymmetry distribution. The horizontal bars show the statistical uncertainty and the full vertical lines show the total uncertainty on each point. The total uncertainty is the sum in quadrature of the statistical and systematic uncertainties. The solid (dashed) line is the theoretical prediction for the asymmetry using the CTEQ6.6 (MRST04NLO) central PDF set. The shaded band is the uncertainty band determined using the 44 CTEQ6.6 PDF uncertainty sets. All three were determined using resbos with photos.

Figure 2

The folded electron charge asymmetry distribution in two electron $E_T$ bins: $25<E_T<35\mathrm{GeV}$ for (a) and $E_T>35\mathrm{GeV}$ for (b). In each plot, the horizontal bars show the statistical uncertainty and the full vertical lines show the total uncertainty on each point. The total uncertainty is the sum in quadrature of the statistical and systematic uncertainties. The solid (dashed) line is the theoretical prediction for the asymmetry using the CTEQ6.6 (MRST04NLO) central PDF set. The shaded band is the uncertainty band determined using the 44 CTEQ6.6 PDF uncertainty sets. All three were determined using resbos with photos.