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We revisit the question of hadronic decays of a giga-electron-volt-mass Higgs-like scalar. A number of extensions of the Standard Model predict the Higgs sector with additional light scalars. Currently operating and planned Intensity Frontier experiments will probe for the existence of such particles, while theoretical computations are plagued by uncertainties. The goal of this paper is to bring the results in a consolidated form that can be readily used by experimental groups. To this end, we provide a physically motivated fitting ansatz for the decay width that reproduces the previous nonperturbative numerical analysis. We describe systematic uncertainties of the nonperturbative method and provide explicit examples of the influence of extra resonances above 1.4 GeV onto the total decay width.

Previous fits of sterile neutrino dark matter models to cosmological data assumed a peculiar production mechanism, which is not representative of the best-motivated particle physics models given current data on neutrino oscillations. These analyses ruled out sterile neutrino masses smaller than 8-10 keV. Here we focus on sterile neutrinos produced resonantly. We show that their cosmological signature can be approximated by that of mixed Cold plus Warm Dark Matter (CWDM). We use recent results on LambdaCWDM models to show that for each mass greater than or equal to 2 keV, there exists at least one model of sterile neutrino accounting for the totality of dark matter, and consistent with Lyman-alpha and other cosmological data. Resonant production occurs in the framework of the nuMSM (the extension of the Standard Model with three right-handed neutrinos). The models we checked to be allowed correspond to parameter values consistent with neutrino oscillation data, baryogenesis and all other dark matter bounds., Comment: 4 pages, 4 figures