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 $(p_T)$ and decaying to a bottom quark-antiquark pair $(b\bar{b})$ is performed using a data set of pp collisions at $\sqrt{s }=13  TeV$ 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 $(b\bar{b})$ 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 $Z→(b\bar{b})$ decays. The $Z→(b\bar{b})$ 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 $H→(b\bar{b})$ with reconstructed $(p_T)>450  GeV$ and in the pseudorapidity range $−2.5<η<2.5$ is $74±48(stat)_{-10}^{+17}(syst)fb$, which is consistent within uncertainties with the standard model prediction.