Softly-broken $$A_4$$ A 4 or $$S_4$$ S 4 3HDMs with stable states

Abstract

Abstract We study multi-Higgs models with a triplet of $$A_4$$ A 4 or $$S_4$$ S 4 symmetry that is softly-broken. Focusing on parameters that softly break the respective symmetries but preserve the directions of the vacuum expectation values of the triplet we analyse the masses of physical states and discuss their decays. In contrast with previously studied symmetries, we find some cases with stable states that are protected by residual symmetries left unbroken by both the soft-breaking parameters and by the vacuum.