Disentangling Sub-GeV Dark Matter from the Diffuse Supernova Neutrino Background using Hyper-Kamiokande

TL;DR

This paper investigates how sub-GeV dark matter annihilating into neutrinos could interfere with the detection and analysis of the Diffuse Supernova Neutrino Background in Hyper-Kamiokande, proposing an on-off analysis to mitigate this effect.

Contribution

It introduces the consideration of sub-GeV dark matter as a background in DSNB detection and demonstrates a method to distinguish it using on-off analysis.

Findings

Dark matter neutrinos can bias DSNB parameter estimation.

On-off analysis can reduce dark matter background effects.

Simulations show potential for improved DSNB signal extraction.

Abstract

The upcoming Hyper-Kamiokande (HyperK) experiment is expected to detect the Diffuse Supernova Neutrino Background (DSNB). This requires to ponder all possible sources of background. Sub-GeV dark matter (DM) which annihilates into neutrinos is a potential background that has not been considered so far. We simulate DSNB and DM signals, as well as backgrounds in the HyperK detector. We find that DM-induced neutrinos could indeed alter the extraction of the correct values of the parameters of interest for DSNB physics. Since the DSNB is an isotropic signal, and DM originates primarily from the Galactic centre, we show that this effect could be alleviated with an on-off analysis.