Measurement of the Electron Charge Asymmetry in InclusiveWProduction inppCollisions ats=7TeV

A measurement of the electron charge asymmetry in inclusive $pp\ensuremath{\rightarrow}W+X\ensuremath{\rightarrow}e\ensuremath{\nu}+X$ production at $\sqrt{s}=7\text{ }\text{ }\mathrm{TeV}$ is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of $840\text{ }\text{ }{\mathrm{pb}}^{\ensuremath{-}1}$. The electron charge asymmetry reflects the unequal production of ${W}^{+}$ and ${W}^{\ensuremath{-}}$ bosons in $pp$ collisions. The electron charge asymmetry is measured in bins of the absolute value of electron pseudorapidity in the range of $|\ensuremath{\eta}|l2.4$. 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.