Measurement of the associated production of a top-antitop-quark pair and a Higgs boson decaying into a b¯b √ pair in pp collisions at √s = 13 TeV using the ATLAS detector at the LHC

Abstract

This paper reports the measurement of Higgsboson production in association with a t -t pair in the H RIGHTWARDS ARROW b-bdecay channel. The analysis uses 140 fb-1 of 13 TeVproton-proton collision data collected with theATLASdetector at theLarge Hadron Collider. The final states with one or two electronsor muons are employed. An excess of events over theexpected background is found with an observed (expected)significance of 4.6 (5.4) standard deviations. The t -tH crosssectionis σt -tH = 411 +101-92 fb = 411+-54(stat.)+85-75(syst.) fbfor a Higgs boson mass of 125.09 GeV, consistent with theprediction of the Standard Model of 507+35-50 fb. The crosssectionis also measured differentially in bins of the Higgsboson transverse momentum within the simplified template cross-section framework.