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

A search for new phenomena in events with missing transverse momentum and a Standard Model (SM) Higgs boson decaying into two photons is presented. This study is based on data collected with the ATLAS detector corresponding to an integrated luminosity of $36.1~\mathrm{fb}^{-1}$ of proton-proton collisions at the LHC at a center-of-mass energy of 13 TeV in 2015 and 2016. No significant excess over the background expectation is observed. 95% confidence level limits are set on the production cross section times branching fraction of the SM Higgs boson decaying into two photons in association with missing transverse momentum in three different theoretical benchmark models. 95% confidence level limits are also set on the observed signal strength in a two-dimensional plane using masses of benchmark models particles. Additionally, the results are interpreted in terms of 90% confidence level limits on the dark matter-nucleon scattering cross section, as a function of the dark matter particle mass, for a spin-independent scenario.