Search for heavy resonances decaying into two Higgs bosons in the b b-bar tau+ tau- final state in proton-proton collisions at sqrt(s) = 13 TeV

A search is presented for massive narrow-width resonances in the mass range of 1–4.5 TeV, decaying into pairs of Higgs bosons (HH). The search uses proton–proton collision data at a center-of-mass energy of 13 TeV collected with the CMS detector at the CERN LHC during 2016–2018, corresponding to an integrated luminosity of 138 fb−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 4.5 TeV. This analysis sets the most sensitive limits to date on X → HH → bb¯ τ+τ− decays in the mass range of 1.4–4.5 TeV.