Linking the Galactic Center excess to invisible Higgs boson decays in the NMSSM

The Galactic Center excess of gamma ray photons can be naturally explained by light Majorana fermions in combination with a pseudoscalar mediator. The next-to-minimal supersymmetric Standard Model (NMSSM) provides exactly these ingredients. We show that for neutralinos with a significant singlino component the Galactic Center excess can be linked to invisible decays of the Standard Model-like Higgs at the LHC. We find predictions for invisible Higgs branching ratios in excess of 50%, easily accessible at the LHC. Constraining the NMSSM through grand-unified-theory (GUT)-scale boundary conditions only slightly affects this expectation. Our results complement earlier NMSSM studies of the Galactic Center excess, which link it to heavy Higgs searches at the LHC.