Long-term neutrino emission from a core-collapse supernova with axion-photon coupling

We perform long-term general-relativistic neutrino-radiation hydrodynamic simulations for core-collapse supernovae (CCSNe) which include the cooling effect induced by the coupling between axion-like particles (ALPs) and photons. We take into account the \kanji{photon} coalescence and the Primakoff effect, and investigate ALPs with the mass of 10\,MeV and the coupling constant $g_{aγ}$ of $1.0\times10^{-9}{\rm \,GeV^{-1}}$ to $7.0\times10^{-9}{\rm \,GeV^{-1}}$. It is found that the effects of the ALP cooling emerge in the late phase rather than the early phase and the ALP luminosities are always lower than the neutrino luminosity in our simulations. We estimate the number of neutrino events for Super-Kamiokande assuming a 10\,kpc CCSN. We conclude that signatures of ALPs could be found in the long-term neutrino signals from a nearby CCSN event in the future, even if $g_{aγ}$ is below an upper limit based on the conventional energy-loss argument.