Evidence for a Standard Model Higgs Boson Produced in Association with a Top Quark Pair and Decaying to Leptons

A search for the standard model Higgs boson produced in association with a top quark pair is presented, using the full pp collision dataset corresponding to an integrated luminosity of 35.9 fb^-1 collected by the CMS experiment at a center of mass energy of √s = 13 TeV. MVA-based event reconstruction techniques are used to identify final states where the Higgs boson decays to either a W, Z or tau pair by selecting events with two isolated same-sign leptons, and b-jets. The observed best-fit \ th signal strength is 1.7^+0.6_-0.5 times the Standard Model prediction, corresponding to a significance of 3.3 standard deviations above the background-only hypothesis. The observed 95% CL upper limit on the signal strength is 2.9 times the Standard Model prediction, compared to the expected upper limit of 1.0^+0.5_-0.3