Measurement of the transverse momentum distribution of W bosons in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper measures the transverse momentum distribution of W bosons in proton-proton collisions at 7 TeV using ATLAS data, comparing results with theoretical predictions and event generators to test QCD models.

Contribution

It provides the first detailed measurement of W boson pT distribution at 7 TeV, using unfolded data and combining electron and muon channels for comparison with QCD predictions.

Findings

Measured W boson pT distribution up to 300 GeV

Results agree with perturbative QCD within uncertainties

Provides data for tuning event generators

Abstract

This paper describes a measurement of the W boson transverse momentum distribution using ATLAS pp collision data from the 2010 run of the LHC at sqrt(s) = 7 TeV, corresponding to an integrated luminosity of about 31 pb^-1. Events from both W -> e nu and W -> mu nu are used, and the transverse momentum of the W candidates is measured through the energy deposition in the calorimeter from the recoil of the W. The resulting distributions are unfolded to obtain the normalized differential cross sections as a function of the W boson transverse momentum. We present results for pTW < 300 GeV in the electron and muon channels as well as for their combination, and compare the combined results to the predictions of perturbative QCD and a selection of event generators.