Inclusive Search for a Highly Boosted Higgs Boson Decaying to a Bottom Quark-Antiquark Pair

Abstract

An inclusive search for the standard model Higgs boson (H) produced with large transverse momentum (pT) and decaying to a bottom quark-antiquark pair (b¯b) is performed using a data set of pp collisions at √s =13 TeV collected with the CMS experiment at the LHC. The data sample corresponds to an integrated luminosity of 35.9 fb−1. A highly Lorentz-boosted Higgs boson decaying to b¯b is reconstructed as a single, large radius jet, and it is identified using jet substructure and dedicated b tagging techniques. The method is validated with Z→b¯b decays. The Z→b¯ b process is observed for the first time in the single-jet topology with a local significance of 5.1 standard deviations (5.8 expected). For a Higgs boson mass of 125 GeV, an excess of events above the expected background is observed (expected) with a local significance of 1.5 (0.7) standard deviations. The measured cross section times branching fraction for production via gluon fusion of H→b¯b with reconstructed p T>450 GeV and in the pseudorapidity range −2.5<η<2.5 is 74 ± 48 (stat)+17−10(syst) fb, which is consistent within uncertainties with the standard model prediction.