Measurement of the cross-section for W boson production in association with b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

TL;DR

This paper measures the production cross-section of W bosons with b-jets in proton-proton collisions at 7 TeV using the ATLAS detector, providing data that tests QCD predictions and improves understanding of W+b-jet processes.

Contribution

First measurement of W+b-jets cross-section at 7 TeV with detailed kinematic dependence using ATLAS data, aligning with NLO QCD calculations.

Findings

Measured W+b-jets cross-section as 7.1 pb with uncertainties

Cross-section consistent with NLO QCD within 1.5 standard deviations

Provided differential cross-sections as functions of jet multiplicity and pT of leading b-jet

Abstract

This paper reports a measurement of the W+b-jets production cross-section in proton-proton collisions at a centre-of-mass energy of 7 TeV at the LHC. These results are based on data corresponding to an integrated luminosity of 4.6 fb-1, collected with the ATLAS detector. Cross-sections are presented as a function of jet multiplicity and of the transverse momentum of the leading b-jet for both the muon and electron decay modes of the W boson. The W+b-jets cross-section, corrected for all known detector effects, is quoted in a limited kinematic range, using jets reconstructed with the anti-k_t clustering algorithm with transverse momentum above 25 GeV and rapidity within +/- 2.1. Combining the muon and electron channels, the fiducial cross-section for W+b-jets is measured to be 7.1 +/- 0.5 (stat) +/- 1.4 (syst) pb, consistent with next-to-leading order QCD calculations within 1.5 standard deviations.