Search for heavy resonances decaying to two Higgs bosons in final states containing four b quarks

TL;DR

This paper reports a search for heavy resonances decaying into pairs of Higgs bosons in four b-quark final states using CMS data at 8 TeV, setting new limits on production cross sections and excluding certain radion masses.

Contribution

First search for heavy resonances decaying to Higgs pairs in four b-quark final states at 8 TeV with advanced jet substructure techniques.

Findings

No evidence for heavy resonances was observed.

Upper limits on cross sections range from 10 to 1.5 fb.

Excluded radion scalar masses between 1.15 and 1.55 TeV.

Abstract

A search is presented for narrow heavy resonances X decaying into pairs of Higgs bosons (H) in proton-proton collisions collected by the CMS experiment at the LHC at sqrt(s) = 8 TeV. The data correspond to an integrated luminosity of 19.7 inverse femtobarns. The search considers HH resonances with masses between 1 and 3 TeV, having final states of two b quark pairs. Each Higgs boson is produced with large momentum, and the hadronization products of the pair of b quarks can usually be reconstructed as single large jets. The background from multijet and t t-bar events is significantly reduced by applying requirements related to the flavor of the jet, its mass, and its substructure. The signal would be identified as a peak on top of the dijet invariant mass spectrum of the remaining background events. No evidence is observed for such a signal. Upper limits obtained at 95% confidence level for the product of the production cross section and branching fraction sigma(gg to X) B(X to HH to b b-bar b b-bar) range from 10 to 1.5 fb for the mass of X from 1.15 to 2.0 TeV, significantly extending previous searches. For a warped extra dimension theory with a mass scale Lambda[R] = 1 TeV, the data exclude radion scalar masses between 1.15 and 1.55 TeV.