Non-thermal neutrinos created by shock acceleration in successful and failed core-collapse supernova

TL;DR

This study demonstrates that shock acceleration in core-collapse supernovae produces high-energy neutrinos, which could be detected on Earth and provide insights into supernova dynamics and neutrino physics.

Contribution

It is the first comprehensive Monte Carlo simulation showing shock acceleration of neutrinos in both successful and failed supernovae, predicting detectable high-energy neutrino signals.

Findings

High-energy neutrinos up to 200 MeV are produced via shock acceleration.

Detection of >80 MeV neutrinos is feasible with current neutrino detectors.

High-energy neutrino signals can reveal supernova inner dynamics and neutrino flavor conversion.

Abstract

We present a comprehensive study of neutrino shock acceleration in core-collapse supernova (CCSN). The leading players are heavy leptonic neutrinos, $\nu_{\mu}$ and $\nu_{\tau}$; the former and latter potentially gain the energy up to $\sim 100$ MeV and $\sim 200$ MeV, respectively, through the shock acceleration. Demonstrating the neutrino shock acceleration by Monte Carlo neutrino transport, we make a statement that it commonly occurs in the early post bounce phase ($\lesssim 50$ ms after bounce) for all massive stellar collapse experiencing nuclear bounce and would reoccur in the late phase ($\gtrsim 100$ ms) for failed CCSNe. This opens up a new possibility to detect high energy neutrinos by terrestrial detectors from Galactic CCSNe; hence, we estimate the event counts for Hyper(Super)-Kamiokande, DUNE, and JUNO. We find that the event count with the energy of $\gtrsim 80$ MeV is a few orders of magnitude higher than that of the thermal neutrinos regardless of the detectors, and muon production may also happen in these detectors by $\nu_{\mu}$ with the energy of $\gtrsim 100$ MeV. The neutrino signals provide a precious information on deciphering the inner dynamics of CCSN and placing a constraint on the physics of neutrino oscillation; indeed, the detection of the high energy neutrinos through charged current reaction channels will be a smoking gun evidence of neutrino flavor conversion.