Sensitivity of multi-PMT Optical Modules in Antarctic Ice to Supernova Neutrinos of MeV energy

TL;DR

This study demonstrates that segmented optical sensors in Antarctic ice can significantly improve detection sensitivity to MeV neutrinos from supernovae, enabling potential detection of extragalactic events with a large sensor array.

Contribution

It introduces a novel detection method using segmented sensors for MeV neutrinos and evaluates its effectiveness for supernova detection in Antarctic ice.

Findings

Detection range up to 269 kpc for a 27 solar mass supernova.

Increasing sensors to 20,000 and reducing background enhances detection rate to 0.08 per year.

Potential to detect extragalactic supernovae with low false alarm rates.

Abstract

New optical sensors with a segmented photosensitive area are being developed for the next generation of neutrino telescopes at the South Pole. In addition to increasing sensitivity to high-energy astrophysical neutrinos, we show that this will also lead to a significant improvement in sensitivity to MeV neutrinos, such as those produced in core-collapse supernovae (CCSN). These low-energy neutrinos can provide a detailed picture of the events after stellar core collapse, testing our understanding of these violent explosions. We present studies on the event-based detection of MeV neutrinos with a segmented sensor and, for the first time, the potential of a corresponding detector in the deep ice at the South Pole for the detection of extra-galactic CCSN. We find that exploiting temporal coincidences between signals in different photocathode segments, a $27\ \mathrm{M}_{\odot}$ progenitor mass CCSN can be detected up to a distance of 269 kpc with a false detection rate of $0.01$ year$^{-1}$ with a detector consisting of 10000 sensors. Increasing the number of sensors to 20000 and reducing the optical background by a factor of 140 expands the range such that a CCSN detection rate of $0.08$ per year is achieved, while keeping the false detection rate at $0.01$ year$^{-1}$.