Limits on right-handed interactions from SN 1987A observations

We consider the emission of light (m_νR0ex0ex 10 MeV right-handed neutrinos from supernova 1987A via right-handed charged- and neutral-current interactions. By requiring that the neutronization process eR^-→νRn does not carry away most of the energy that can be radiated by the supernova, ET0ex0ex0ex0ex (4-5) ×{} 10⁵³ ergs, we exclude the range of values for the right-handed W-boson mass, (3.7-6.7)M_WL {≤} M_WR {≤} (280-500)M_WL for vanishing WL --- WR mixing parameter {ζ}, and for {ζ} {≠} 0 we get (0.4-1.2) ×{} 10^-5 {≤} ${[{{ζ}}²{{0ex}{0ex}}+{{0ex}{0ex}}({M}_{{W}L}⁴{{0ex}{0ex}}/{{0ex}{0ex}}{M}_{{W}R}⁴)]}1/2{{0ex}{0ex}}{≤}(0.02{-}0.07)$. For right-handed $W$ bosons heavier than 300 ${M}_{{W}L}$, a significant ${{ν}}R$ emission may arise from the neutral-current-induced process ${e}⁺{e}^{{-}}{→}{{{ν}}}R{{ν}}R$, as well as $nn{→}nn{ν}{{ν}}$ mediated by an extra gaugae boson $Z{'}$. In this case, for an appropriately defined effective mass ${M}N$ for $Z{'}$, we find the excluded region $(2.4{-}4.3){M}_{{W}L}<{M}N<(30{-}85){M}_{{W}L}$, mainly dependent on the core temperature and density profile.