A search for dark matter produced in association with a dark Higgs boson decaying into a Higgs boson pair in 3b or 4b final states using pp collisions at SQUARE ROOTs = 13 TeV with the ATLAS detector

Abstract

A search is performed for dark matter particles produced in association with aresonant pair of Higgs bosons using 140 fb-1 of proton-proton collisions at a centre-of-massenergy of 13TeV recorded by the ATLAS detector at the Large Hadron Collider. Thissignature is expected in some extensions of the Standard Model predicting the productionof dark matter particles, and is interpreted in terms of a dark Higgs model containing a Z'mediator in which the dark Higgs boson s decays into a pair of Higgs bosons. The darkHiggs boson is reconstructed through final states with at least three b-tagged jets, producedby the pair of Higgs boson decays, in events with significant missing transverse momentumconsistent with the presence of dark matter. The observed data are found to be in goodagreement with Standard Model predictions, constraining scenarios with dark Higgs bosonmasses within the range of 250 to 400 GeV and Z' mediators up to 2.3TeV.