Measurement of the electron charge asymmetry in inclusive W production in pp collisions at sqrt(s) = 7 TeV

TL;DR

This paper reports a precise measurement of the electron charge asymmetry in W boson production at 7 TeV proton-proton collisions, providing new constraints on parton distribution functions using CMS data.

Contribution

It presents the first detailed measurement of electron charge asymmetry in W production at 7 TeV, improving constraints on parton distribution functions.

Findings

Asymmetry increases from 0.1 to 0.2 with pseudorapidity

Measurement precision better than 7%

Provides new constraints for PDFs

Abstract

A measurement of the electron charge asymmetry in inclusive pp to W + X to e nu + X production at sqrt(s) = 7 TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840 inverse picobarns. The electron charge asymmetry reflects the unequal production of positive and negative W bosons in pp collisions. The electron charge asymmetry is measured in bins of absolute value of electron pseudorapidity in the range of abs(eta) < 2.4. The asymmetry rises from about 0.1 to 0.2 as a function of the pseudorapidity and is measured with a relative precision better than 7%. This measurement provides new stringent constraints for parton distribution functions.