Supernova constraints on dark flavored sectors
Jorge Martin Camalich, Jorge Terol-Calvo, Laura Tolós, Robert Ziegler
Abstract
Proto-neutron stars forming a few seconds after core-collapse supernovae are hot and dense environments where hyperons can be efficiently produced by weak processes. By making use of various state-of-the-art supernova simulations combined with the proper extensions of the equations of state including $\mathrm{\ensuremath{\Lambda}}$ hyperons, we calculate the cooling of the star induced by the emission of dark particles ${X}^{0}$ through the decay $\mathrm{\ensuremath{\Lambda}}\ensuremath{\rightarrow}n{X}^{0}$. Comparing this novel energy-loss process to the neutrino cooling of SN 1987A allows us to set a stringent upper limit on the branching fraction, $\mathrm{BR}(\mathrm{\ensuremath{\Lambda}}\ensuremath{\rightarrow}n{X}^{0})\ensuremath{\le}8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}9}$, that we apply to massless dark photons and axions with flavor-violating couplings to quarks. We find that the new supernova bound can be orders of magnitude stronger than other limits in dark-sector models.