UC Irvine

This paper presents a measurement of the production cross-section of a W boson associated with one or two jets, where at least one jet originates from a b-quark. The data are collected with the ATLAS detector at the LHC in proton-proton collisions at s=13$$ \sqrt{s}=13 $$ TeV, corresponding to an integrated luminosity of 140 fb-1. Differential cross-sections are presented as a function of the transverse momentum of the b-jet for both the electron and muon decay modes of the W boson. The results corrected for all detector effects are presented in a fiducial region defined with basic lepton and jet kinematics, and compared with theoretical predictions. The combined fiducial cross-section of W + b-jets for the electron and muon channels is measured to be 16.6 ± 1.9 pb, which is consistent with the next-to-leading-order QCD prediction of 16.8 ± 2.3 pb. The relative precision of this measurement is improved by approximately a factor of two compared with the previous ATLAS measurement at s=7$$ \sqrt{s}=7 $$ TeV.