Collider Cross Talk

Inclusive Higgs boson search using $H \to b \bar b $ decays

by Javier Mauricio Duarte (Fermi National Accelerator Lab. (US)), Mrinal Dasgupta (University of Manchester (GB))

Europe/Zurich
4/2-011 - TH common room (CERN)

4/2-011 - TH common room

CERN

15
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Description

An observation of the Higgs boson decaying to a bottom quark-antiquark pair in the gluon fusion production mode was long considered impossible due to the overwhelming background from QCD multijet production of bottom quarks. However, we can access this process in the boosted dijet topology, in which the Higgs to bb system is reconstructed as a single, large-radius jet. In this talk, we will describe the theory of jet substructure and grooming and how it is applied in the first search for boosted Higgs to bb at the LHC. The dominant QCD multijet background is estimated using a data-driven sideband method. We will detail the background estimation strategy and signal extraction, which is validated with Z to bb decays. The Z to bb process is observed with a local significance of 5.1 standard deviations for the first time in the single-jet topology. An excess of Higgs to bb events above the expected background is observed with a local significance of 1.5 standard deviations.