Supernova Constraints on Dark Flavored Sectors

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 equations state including $\Lambda$ hyperons, we calculate cooling star induced emission dark particles $X^0$ through decay $\Lambda\to n X^0$. Comparing this novel energy-loss process to neutrino SN 1987A allows us set stringent upper limit on branching fraction, BR$(\Lambda\to X^0)\leq 8\times10^{-9}$, that apply massless photons axions flavor-violating couplings quarks. We find new bound orders magnitude stronger than other limits in dark-sector models.