Measurement of the cross-section for the production of a W boson in association with b-jets in pp collisions at √s=13 TeV with the ATLAS detector

A bstract 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 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 s = 7 TeV.