Prospects for Detecting the Diffuse Supernova Neutrino Background with JUNO

TL;DR

This paper evaluates JUNO's potential to detect the diffuse supernova neutrino background using inverse-beta-decay, analyzing backgrounds, and optimizing detection techniques to achieve significant confidence levels within a decade.

Contribution

It provides a detailed assessment of JUNO's detection prospects for DSNB, including background reduction strategies and realistic sensitivity estimates.

Findings

JUNO can reach 3σ significance in 3 years

JUNO can achieve >5σ detection after 10 years

The atmospheric neutrino background is the most critical challenge

Abstract

We present the detection potential for the diffuse supernova neutrino background (DSNB) at the Jiangmen Underground Neutrino Observatory (JUNO), using the inverse-beta-decay (IBD) detection channel on free protons. We employ the latest information on the DSNB flux predictions, and investigate in detail the background and its reduction for the DSNB search at JUNO. The atmospheric neutrino induced neutral current (NC) background turns out to be the most critical background, whose uncertainty is carefully evaluated from both the spread of model predictions and an envisaged \textit{in situ} measurement. We also make a careful study on the background suppression with the pulse shape discrimination (PSD) and triple coincidence (TC) cuts. With latest DSNB signal predictions, more realistic background evaluation and PSD efficiency optimization, and additional TC cut, JUNO can reach the significance of 3$\sigma$ for 3 years of data taking, and achieve better than 5$\sigma$ after 10 years for a reference DSNB model. In the pessimistic scenario of non-observation, JUNO would strongly improve the limits and exclude a significant region of the model parameter space.