Measurement of jet substructure observables in t(t)over-bar events from proton-proton collisions at root s=13 TeV

Abstract

A measurement of jet substructure observables is presented using t ¯ t events in the lepton + jets channel from proton-proton collisions at √ s = 13 TeV recorded by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9 fb − 1 . Multiple jet substructure observables are measured for jets identified as bottom, light-quark, and gluon jets, as well as for inclusive jets (no flavor information). The results are unfolded to the particle level and compared to next-to-leading-order predictions from powheg interfaced with the parton shower generators pythia 8 and herwig 7, as well as from sherpa 2 and Dire 2. A value of the strong coupling at the Z boson mass, α S ( m Z ) = 0.11 5 + 0.015 − 0.013 , is extracted from the substructure data at leading-order plus leading-log accuracy.