The SNO+ Experiment

TL;DR

The SNO+ experiment is a large underground detector designed to search for neutrinoless double beta decay using liquid scintillator loaded with tellurium, while also exploring various neutrino physics topics.

Contribution

This paper provides a comprehensive overview of the SNO+ detector design, construction, upgrades, and its broad physics program beyond neutrinoless double beta decay.

Findings

Successful detector design and construction at SNOLAB

Low background environment enabling sensitive decay searches

Potential to probe Majorana neutrino mass in future phases

Abstract

The SNO+ experiment is located 2 km underground at SNOLAB in Sudbury, Canada. A low background search for neutrinoless double beta ($0\nu\beta\beta$) decay will be conducted using 780 tonnes of liquid scintillator loaded with 3.9 tonnes of natural tellurium, corresponding to 1.3 tonnes of $^{130}$Te. This paper provides a general overview of the SNO+ experiment, including detector design, construction of process plants, commissioning efforts, electronics upgrades, data acquisition systems, and calibration techniques. The SNO+ collaboration is reusing the acrylic vessel, PMT array, and electronics of the SNO detector, having made a number of experimental upgrades and essential adaptations for use with the liquid scintillator. With low backgrounds and a low energy threshold, the SNO+ collaboration will also pursue a rich physics program beyond the search for $0\nu\beta\beta$ decay, including studies of geo- and reactor antineutrinos, supernova and solar neutrinos, and exotic physics such as the search for invisible nucleon decay. The SNO+ approach to the search for $0\nu\beta\beta$ decay is scalable: a future phase with high $^{130}$Te-loading is envisioned to probe an effective Majorana mass in the inverted mass ordering region.