Search for Higgs boson pair production in the four b quark final state in proton-proton collisions at $\sqrt{s} =$ 13 TeV

TL;DR

This paper reports a search for Higgs boson pair production in the four b quark final state using 13 TeV proton-proton collision data from the CMS detector, setting new constraints on production cross section and couplings.

Contribution

It presents the most stringent constraints to date on Higgs pair production cross section and the $ abla_ ext{2V}$ coupling, using a large dataset and focusing on the four b quark final state.

Findings

No significant deviation from background observed.

Upper limit on Higgs pair production cross section at 3.9 times the SM prediction.

Constraints on Higgs self-coupling modifier $ abla_ ext{lambda}$ and $ abla_ ext{2V}$ coupling.

Abstract

A search for pairs of Higgs bosons produced via gluon and vector boson fusion is presented, focusing on the four b quark final state. The data sample consists of proton-proton collisions at a center-of-mass energy of 13 TeV, collected with the CMS detector at the LHC, and corresponds to an integrated luminosity of 138 fb$^{-1}$. No deviation from the background-only hypothesis is observed. A 95% confidence level upper limit on the Higgs boson pair production cross section is observed at 3.9 times the standard model prediction for an expected value of 7.8. Constraints are also set on the modifiers of the Higgs field self-coupling, $\kappa_\lambda$, and of the coupling of two Higgs bosons to two vector bosons, $\kappa_\mathrm{2V}$. The observed (expected) allowed intervals at the 95% confidence level are $-$2.3 $\lt$ $\kappa_\lambda$ $\lt$ 9.4 ($-$5.0 $\lt$ $\kappa_\lambda$ $\lt$ 12.0) and $-$0.1 $\lt$ $\kappa_\mathrm{2V}$ $\lt$ 2.2 ($-$0.4 $\lt$ $\kappa_\mathrm{2V}$ $\lt$ 2.5). These are the most stringent observed constraints to date on the HH production cross section and on the $\kappa_\mathrm{2V}$ coupling.