Limits on heavy neutral leptons, Z^′ bosons and majorons from high-energy supernova neutrinos

Light hypothetical particles with masses up to $\mathcal{O}\left(100\right)$ \( \mathcal{O}(100) \) MeV can be produced in the core of supernovae. Their subsequent decays to neutrinos can produce a flux component with higher energies than the standard flux. We study the impact of heavy neutral leptons, Z^′ bosons, in particular $\mathrm{U}{\left(1\right)}_{L_{\mu }-L_{\tau }}$ \( \textrm{U}{(1)}_{L_{\mu }-{L}_{\tau }} \) and U(1)_B−L gauge bosons, and majorons coupled to neutrinos flavor-dependently. We obtain new strong limits on these particles from no events of high-energy SN 1987A neutrinos and their future sensitivities from observations of galactic supernova neutrinos.