Search for new particles in an extended Higgs sector with four b quarks in the final state at √s = 13 TeV

Abstract

A search for a massive resonance X decaying to a pair of spin-0 bosons φ that themselves decay to pairs of bottom quarks, is presented. The analysis is restricted to the mass ranges mφ from 25 to 100 GeV and mX from 1 to 3 TeV. For these mass ranges, the decay products of each φ boson are expected to merge into a single large-radius jet. Jet substructure and flavor identification techniques are used to identify these jets. The search is based on CERN LHC proton-proton collision data at √s = 13 TeV, collected with the CMS detector in 2016–2018, corresponding to an integrated luminosity of 138 fb−1. Model-specific limits, where the two new particles arise from an extended Higgs sector, are set on the product of the production cross section and branching fraction for X → φφ → (bb)(bb) as a function of the resonances’ masses, where both the X → φφ and φ → bb branching fractions are assumed to be 100%. These limits are the first of their kind on this process, ranging between 30 and 1 fb at 95% confidence level for the considered mass ranges.