Discovery potential for supernova relic neutrinos with slow liquid scintillator detectors

Abstract

Detection of supernova relic neutrinos could provide key support for our current understanding of stellar and cosmological evolution, and precise measurements of these neutrinos could yield novel insights into the universe. In this paper, we studied the detection potential of supernova relic neutrinos using linear alkyl benzene (LAB) as a slow liquid scintillator. The linear alkyl benzene features good separation of Cherenkov and scintillation lights, thereby providing a new route for particle identification. We further addressed key issues in current experiments, including (1) the charged current background of atmospheric neutrinos in water Cherenkov detectors and (2) the neutral current background of atmospheric neutrinos in typical liquid scintillator detectors. A kiloton-scale LAB detector at Jinping with O(10) years of data could discover supernova relic neutrinos with a sensitivity comparable to that of large-volume water Cherenkov detectors, typical liquid scintillator detectors, and liquid argon detectors.

Sensitivity to neutrino-antineutrino transitions for boron neutrinos

“…This delays the scintillation process and thus separates from the Cherenkov light. This can significantly increase the background rejection capability using the particle identification method (PID) [22].…”

“…• Reactor neutrino and geo-neutrino: Reactor neutrino and geo-neutrino are generated from the fission of Uranium and Putonium isotopes in the reactors, and beta decays of Uranium and Thorium inside the terrestrial crust, respectively. [22]. Fraction of boron spectrum for each window is shown in round brackets.…”

“…This can be largely suppressed by detector shielding. Furthermore, the prompt signal can be identified efficiently by particle identification with pulse shape discrimination (PSD) [22].…”

“…The choice of lower bound (8.5 MeV) is based on [15]. In this window the background consists of atmospheric NC events [22] and the tail of reactor spectrum. It should be noted that the tail may have quite a large uncertainty.…”

Design and analysis of a 1-ton prototype of the Jinping Neutrino Experiment

“…The Jinping Neutrino Experiment (hereafter referred to as the Jinping experiment) was proposed in 2015 [1], and several related studies were done thereafter [2][3][4][5]. With the advantage of the China Jinping Underground Laboratory (CJPL), which is located 2400 m under the Jinping Mountain in Sichuan, China, the Jinping experiment will perform an in-depth research on the solar neutrino and geo-neutrino physics.…”