Search for Higgs boson pair production in association with a vector boson in $pp$ collisions at $\sqrt{s}=$ 13 TeV with the ATLAS detector

The collaboration
CERN-EP-2022-159, 2022.

Abstract (data abstract)
CERN-LHC. A search for Higgs boson pair ($hh$) production in association with a vector boson ($W\; {\textrm or}\; Z$) is presented, using 139 $fb^{-1}$ of proton--proton collision data at $\sqrt{s}=13\,\text{TeV}$ recorded with the ATLAS detector at the Large Hadron Collider. The search is performed in final states in which the vector boson decays leptonically ($W\to\ell\nu,\, Z\to\ell\ell,\nu\nu$ with $\ell=e, \mu$) and the Higgs bosons each decay into a pair of $b$-quarks. It targets $Vhh$ signals from both non-resonant $hh$ production, present in the Standard Model (SM), and resonant $hh$ production, as predicted in some SM extensions. For the resonant search, upper limits on the production cross-sections are derived for two specific models: one is the production of a vector boson along with a neutral heavy scalar resonance $H$, in the mass range 260--1000 GeV, that decays into $hh$, and the other is the production of a heavier neutral pseudoscalar resonance $A$ that decays into a $Z$ boson and $H$ boson, where the $A$ boson mass is 360--800 GeV and the $H$ boson mass is 260--400 GeV. Constraints are also derived in the parameter space of two-Higgs-doublet models.