Search for heavy resonances decaying into two Higgs bosons in the $\mathrm{b\bar{b}}\tau^+\tau^-$ final state in proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper reports a search for heavy narrow-width resonances decaying into Higgs boson pairs in the b-bbar tau-tau final state using 13 TeV proton-proton collision data, setting the most sensitive limits to date in the 1.4-4.5 TeV mass range.

Contribution

First search targeting the X→HH→bbττ decay channel at high masses with the CMS detector, providing the most stringent limits to date.

Findings

No significant excess observed over background.

Set upper limits on production cross section for resonances between 1 and 4.5 TeV.

Most sensitive limits to date for this decay channel.

Abstract

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 $\to$ HH $\to$ $\mathrm{b\bar{b}}\tau^+\tau^-$. It uses a single large jet to reconstruct the H $\to$ $\mathrm{b\bar{b}}$ decay, while the H $\to$ $\tau^+\tau^-$ decay products can either be contained within a single large 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 HH production for masses between 1 and 4.5 TeV. This analysis sets the most sensitive limits to date on X $\to$ HH $\to$ $\mathrm{b\bar{b}}\tau^+\tau^-$ decays in the mass range of 1.4 to 4.5 TeV.