A search for dark matter produced in association with a dark Higgs boson decaying into a Higgs boson pair in 3$b$ or 4$b$ final states using $pp$ collisions at $\sqrt{s}=13$ TeV with the ATLAS detector

TL;DR

This paper reports a search for dark matter produced alongside a dark Higgs boson decaying into Higgs pairs, using 13 TeV proton-proton collision data, finding no significant deviation from the Standard Model and setting limits on model parameters.

Contribution

First search for dark matter with a dark Higgs boson decaying into Higgs pairs in 3b or 4b final states at 13 TeV with the ATLAS detector.

Findings

No significant excess observed over Standard Model predictions.

Constraints placed on dark Higgs boson masses between 250 and 400 GeV.

Limits set on Z' mediator masses up to 2.3 TeV.

Abstract

A search is performed for dark matter particles produced in association with a resonant pair of Higgs bosons using 140 fb$^{-1}$ of proton--proton collisions at a centre-of-mass energy of 13 TeV recorded by the ATLAS detector at the Large Hadron Collider. This signature is expected in some extensions of the Standard Model predicting the production of 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 dark Higgs boson is reconstructed through final states with at least three $b$-tagged jets, produced by the pair of Higgs boson decays, in events with significant missing transverse momentum consistent with the presence of dark matter. The observed data are found to be in good agreement with Standard Model predictions, constraining scenarios with dark Higgs boson masses within the range of 250 to 400 GeV and $Z'$ mediators up to 2.3 TeV.