Search for t t ¯ H $$ \mathrm{t}\overline{\mathrm{t}}\mathrm{H} $$ production in the all-jet final state in proton-proton collisions at s = 13 $$ \sqrt{s}=13 $$ TeV

Abstract

A search is presented for the associated production of a Higgs boson with a top quark pair in the all-jet nal state. Events containing seven or more jets are selected from a sample of proton-proton collisions at ps = 13TeV collected with the CMS detector at the LHC in 2016, corresponding to an integrated luminosity of 35.9 fb􀀀1. To separate the t tH signal from the irreducible t t + b b background, the analysis assigns leading order matrix element signal and background probability densities to each event. A likelihoodratio statistic based on these probability densities is used to extract the signal. The results are provided in terms of an observed t tH signal strength relative to the standard model production cross section = = SM, assuming a Higgs boson mass of 125 GeV. The best t value is ^ = 0:9 0:7(stat) 1:3(syst) = 0:9 1:5 (tot), and the observed and expected upper limits are, respectively, < 3:8 and < 3:1 at 95% con dence levels.