Search for dark matter in events with missing transverse momentum and a Higgs boson decaying into two photons in $pp$ collisions at $\sqrt{s} = 13$ TeV with the ATLAS detector

TL;DR

This paper reports a search for dark matter particles in proton-proton collisions at 13 TeV, focusing on events with missing transverse momentum and a Higgs decaying into two photons, setting limits on simplified models.

Contribution

First search to analyze events with a Higgs decaying into two photons and missing transverse momentum for dark matter detection at the LHC.

Findings

No significant excess over Standard Model predictions.

Limits set on models with vector or pseudoscalar mediators.

Analyzed 139 fb$^{-1}$ of data from 2015-2018.

Abstract

A search for dark-matter particles in events with large missing transverse momentum and a Higgs boson candidate decaying into two photons is reported. The search uses $139$ fb$^{-1}$ of proton-proton collision data collected at $\sqrt{s}=13$ TeV with the ATLAS detector at the CERN LHC between 2015 and 2018. No significant excess of events over the Standard Model predictions is observed. The results are interpreted by extracting limits on three simplified models that include either vector or pseudoscalar mediators and predict a final state with a pair of dark-matter candidates and a Higgs boson decaying into two photons.