W and Z Boson Cross Section and W Asymmetry at CMS

TL;DR

This paper reports measurements of W and Z boson production rates and asymmetries in proton-proton collisions at 7 TeV using CMS data, confirming consistency with theoretical predictions and providing insights into parton distribution functions.

Contribution

First measurement of W and Z boson cross sections and asymmetries at 7 TeV with CMS, validating NNLO QCD calculations and PDFs.

Findings

Measured inclusive W and Z cross sections agree with NNLO QCD.

W/Z ratio and W+/- asymmetries match theoretical predictions.

Differential W asymmetry as a function of lepton pseudorapidity provided.

Abstract

We report the measurement of the rates and asymmetries of inclusive and differential production of W and Z vector bosons in pp collision at $\sqrt{s}$=7 TeV. The data consists of 36 $pb^{-1}$ collected in the Compact Muon Solenoid (CMS) detector at the Large Hadron Collider (LHC). The measured inclusive cross sections are $\sigma(pp\to WX)\times B(W\to \ell\nu) = 10.31 \pm 0.02 (stat.) \pm 0.09 (syst.) \pm 0.10 (th.) \pm 0.41 (lumi.)$ nb and $\sigma(pp\to ZX)\times B(Z\to \ell\ell) = 0.975 \pm 0.007 (stat.) \pm 0.007 (syst.) \pm 0.018 (th.) \pm 0.039 (lumi.)$ nb. The measured inclusive cross sections and also its ratio of W to Z or $W^{+}$ to $W^{-}$ agree with NNLO QCD cross section calculations and current parton distribution functions (PDFs). The differential production asymmetry of W boson as a function of the lepton pseudorapidity in the final state is also measured and compared with various PDFs.