Search for Higgs boson pair production in the $\gamma\gamma\mathrm{b\overline{b}}$ final state in pp collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper reports a search for Higgs boson pair production in the gamma-gamma and b-bbar final state using 13 TeV LHC data, setting limits on new particles and Higgs self-coupling.

Contribution

It provides the most restrictive constraints to date on the Higgs self-coupling and searches for new resonant particles in Higgs pair production.

Findings

No significant deviation from the Standard Model observed.

Excludes nonresonant production cross section above 2.0 fb at 95% CL.

Constrains Higgs self-coupling parameter within -11 to 17 at 95% CL.

Abstract

A search is presented for the production of a pair of Higgs bosons, where one decays into two photons and the other one into a bottom quark-antiquark pair. The analysis is performed using proton-proton collision data at $\sqrt{s} =$ 13 TeV recorded in 2016 by the CMS detector at the LHC, corresponding to an integrated luminosity of 35.9 fb$^{-1}$. The results are in agreement with standard model (SM) predictions. In a search for resonant production, upper limits are set on the cross section for new spin-0 or spin-2 particles. For the SM-like nonresonant production hypothesis, the data exclude a product of cross section and branching fraction larger than 2.0 fb at 95% confidence level (CL), corresponding to about 24 times the SM prediction. Values of the effective Higgs boson self-coupling $\kappa_\lambda$ are constrained to be within the range $-$11 < $\kappa_\lambda$ < 17 at 95% CL, assuming all other Higgs boson couplings are at their SM value. The constraints on $\kappa_\lambda$ are the most restrictive to date.