Detecting the Diffuse Supernova Neutrino Background in the future Water-based Liquid Scintillator Detector Theia

Understand

A large-scale neutrino observatory based on Water-based Liquid Scintillator (WbLS) will be excellently suited for a measurement of the Diffuse Supernova Neutrino Background (DSNB).

• The WbLS technique offers high signal efficiency and effective suppression of the otherwise overwhelming background from neutral-current interactions of atmospheric neutrinos.
• To illustrate this, we investigate the DSNB sensitivity for two configurations of the future Theia detector by developing the expected signal and background rejection efficiencies along a full analysis chain.
• Based on a statistical analysis of the remaining signal and background rates, we find that a rather moderate exposure of 190kt$\cdot$yrs will be sufficient to claim a ($5\sigma$) discovery of the faint DSNB signal for standard model assumptions.