A deuterated liquid scintillator for supernova neutrino detection

TL;DR

This paper proposes a 1 kton deuterated liquid scintillator detector for supernova neutrino detection, capable of measuring all neutrino flavors through neutral current interactions and extracting spectral information from proton recoil signals.

Contribution

It introduces a novel deuterium-based detector design that can detect all neutrino flavors and analyze their spectra via neutral current interactions, enhancing supernova neutrino observation capabilities.

Findings

Approximately 435 neutral current events expected from a supernova at 10 kpc.

Detection of about 170 $ u_e$ and 108 $ar{ u}_e$ charged current events.

Potential to extract neutrino spectral information from proton recoil measurements.

Abstract

For the next galactic supernova, operational neutrino telescopes will measure the neutrino flux several hours before their optical counterparts. Existing detectors, relying mostly on charged current interactions, are mostly sensitive to $\bar{\nu}_e$ and to a lesser extent to $\nu_e$. In order to measure the flux of other flavors ($\nu_{\mu},\bar{\nu}_{\mu},\nu_{\tau},\text{and}~\bar{\nu}_{\tau}$), we need to observe their neutral current interactions with the detector. Such a measurement is not only crucial for overall normalization of the supernova neutrino flux but also for understanding the intricate neutrino oscillation physics. A deuterium based detector will be sensitive to all neutrino flavors. In this paper, we propose a 1 kton deuterated liquid scintillator (DLS) based detector that will see about 435 neutral current events and 170 (108) charged current $\nu_e$ ($\bar{\nu}_e$) events from a fiducial supernova at a distance of 10 kpc from Earth. We explore the possibility of extracting spectral information from the neutral current channel $\overset{\scriptscriptstyle(-)}{\nu} d \rightarrow \overset{\scriptscriptstyle(-)}{\nu}np$ by measuring the quenched kinetic energy of the proton in the final state, where the neutron in the final state is tagged and used to reduce backgrounds. We also discuss the secondary interactions of the recoil neutrons in the detector.