Exciting Prospects for Detecting Late-Time Neutrinos from Core-Collapse Supernovae

TL;DR

Detecting late-time neutrinos from core-collapse supernovae offers unprecedented insights into proto-neutron star cooling, with current and future detectors capable of capturing detailed signals that can reveal the supernova's core physics and black hole formation.

Contribution

This study provides the first comprehensive analysis of neutrino detection during the proto-neutron star cooling phase across all flavors and detector types, highlighting the potential for high-statistics observations.

Findings

Event yields after 10 seconds far exceed 1987A data

Super-Kamiokande could detect ~250 $ar{ u}_e$ events to 50s

DUNE could detect ~110 $ u_e$ events to 40s

Abstract

The importance of detecting neutrinos from a Milky Way core-collapse supernova is well known. An under-studied phase is proto-neutron star cooling. For SN 1987A, this seemingly began at about 2 s, and is thus probed by only 6 of the 19 events (and only the $\bar{\nu}_e$ flavor) in the Kamiokande-II and IMB detectors. With the higher statistics expected for present and near-future detectors, it should be possible to measure detailed neutrino signals out to very late times. We present the first comprehensive study of neutrino detection during the proto-neutron star cooling phase, considering a variety of outcomes, using all flavors, and employing detailed detector physics. For our nominal model, the event yields (at 10 kpc) after 10 s -- the approximate duration of the SN 1987A signal -- far exceed the entire SN 1987A yield, with $\simeq$250 $\bar{\nu}_e$ events (to 50 s) in Super-Kamiokande, $\simeq$110 $\nu_e$ events (to 40 s) in DUNE, and $\simeq$10 $\nu_\mu, \nu_\tau, \bar{\nu}_\mu, \bar{\nu}_\tau$ events (to 20 s) in JUNO. These data would allow unprecedented probes of the proto-neutron star, including the onset of neutrino transparency and hence its transition to a neutron star. If a black hole forms, even at very late times, this can be clearly identified. But will the detectors fulfill their potential for this perhaps once-ever opportunity for an all-flavor, high-statistics detection of a core collapse? Maybe. Further work is urgently needed, especially for DUNE to thoroughly investigate and improve its MeV capabilities.