Search for resonant pair production of Higgs bosons in the $\mathrm{b\bar{b}b\bar{b}}$ final state using large-area jets in proton-proton collisions at $\sqrt{s}$ = 13 TeV

TL;DR

This paper searches for resonant Higgs boson pair production in the four b-quark final state using CMS data at 13 TeV, setting limits on models with extra dimensions and excluding certain mass ranges for new particles.

Contribution

First search to analyze Higgs pair production in the bbbb final state with large-area jets at 13 TeV, providing new constraints on warped extradimensional models.

Findings

No significant excess observed over standard model expectations.

Set upper limits on cross sections for radion and graviton models.

Excluded graviton masses below 1.2 TeV and radion masses below 2.6-2.9 TeV.

Abstract

A search is presented for the resonant production of a pair of standard model-like Higgs bosons using data from proton-proton collisions at a centre-of-mass energy of 13 TeV, collected by the CMS experiment at the CERN LHC in 2016-2018, corresponding to an integrated luminosity of 138 fb$^{-1}$. The final state consists of two b quark-antiquark pairs. The search is conducted in the region of phase space where at least one of the pairs is highly Lorentz-boosted and is reconstructed as a single large-area jet. The other pair may be either similarly merged or resolved, the latter reconstructed using two b-tagged jets. The data are found to be consistent with standard model processes and are interpreted as 95% confidence level upper limits on the product of the cross sections and the branching fractions of the spin-0 radion and the spin-2 bulk graviton that arise in warped extradimensional models. The limits set are in the range 9.74-0.29 fb and 4.94-0.19 fb for a narrow radion and a graviton, respectively, with masses between 1 and 3 TeV. For a radion and for a bulk graviton with widths 10% of their masses, the limits are in the range 12.5-0.35 fb and 8.23-0.23 fb, respectively, for the same masses. These limits result in the exclusion of a narrow-width graviton with a mass below 1.2 TeV, and of narrow and 10%-width radions with masses below 2.6, and 2.9 TeV, respectively.