Search for heavy resonances decaying into two Higgs bosons in the bb ̄τ+τ- final state in proton–proton collisions at s=13TeV

A search is presented for massive narrow-width resonances in the mass range of 1–4.5TeV, decaying into pairs of Higgs bosons (HH). The search uses proton–proton collision data at a center-of-mass energy of 13TeV collected with the CMS detector at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of 138fb-1. The analysis targets final states where one Higgs boson decays into a pair of bottom quarks and the other into a pair of tau leptons, X→HH→bb¯τ+τ-. It uses a single large radius jet to reconstruct the H→bb¯ decay, while the H→τ+τ- decay products can either be contained within a single large radius jet or appear as two isolated tau leptons. The observed data are consistent with standard model background expectations. Upper limits at 95% confidence level are set on the production cross section for resonant HHproduction for masses between 1 and 4.5TeV. This analysis sets the most sensitive limits to date on X→HH→bb¯τ+τ- decays in the mass range of 1.4–4.5TeV.