$b$-jet energy scale calibration using $t\bar{t}$ lepton+jets events with the ATLAS Run 2 data

Many Standard Model (SM) processes and potential new phenomena at the LHC produce final states with $b$-jets. To properly reconstruct the kinematic of processes producing $b$-jets, an accurate calibration of their energy is crucial. Due to the larger $b$-quark mass, the radiation pattern of $b$-quark induced showers is different than for light quarks or gluons, which in turn can cause a different energy response in the ATLAS detector. This presentation discusses the first $b$-jet energy calibration performed in situ by the ATLAS collaboration. The energy correction of $b$-tagged jets and its uncertainties have been measured both inclusively and differentially as a function of the transverse momentum of the $b$-tagged jets, using a template method that compares the top quark invariant mass distributions in data and simulation using hadronic top-quark decays ($t\to Wb\to q\bar{q}b$) in $t\bar{t}$ lepton+jets events. The full ATLAS Run 2 dataset was used. The energy correction for $b$-tagged jets in data is consistent with unity, with an uncertainty of 2.5% for the inclusive measurement, and decreasing from 4% to 1.9% for $b$-tagged jet transverse momenta increasing between $30$ and $500$ GeV for the differential measurement.