SNO+: Ton-scale Search for Double Beta Decay

by Dr Ana Sofia Inácio (Department of Physics, University of Oxford)

Wednesday 19 Mar 2025, 14:00 → 15:00 Portugal

Sala de Conferências (Departamento de Física FCTUC)

SNO+ is a large liquid scintillator detector with the main physics goal of searching for the neutrinoless double-beta decay of ¹³⁰Te. Neutrinoless double-beta decay is a lepton-number-violating nuclear transition forbidden by the Standard Model, whose observation would provide us with fundamental insights regarding the neutrino mass scale and ordering (two are possible: ”normal” or ”inverted”) and would prove the Majorana nature of the neutrino, which could have consequences for our understanding of the matter/antimatter asymmetry in the universe.
SNO+ started by acquiring data as a kiloton-scale pure-water Cherenkov detector between May 2017 and June 2019, and since April 2022, it is taking data with 780 tonnes of liquid scintillator LAB with 2.2 g/L PPO concentration. The high light yield, low background levels, and continually increasing livetime, allow the SNO+ collaboration to perform measurements of solar neutrinos, antineutrinos from reactors and the Earth, and perform searches for other rare events. The scintillator phase is also critical for understanding the detector response and studying all radioactive backgrounds prior to the tellurium loading. In a first phase, 3900 kg of natural tellurium (0.5% loading) will be added to the scintillator for a predicted sensitivity of about 2×10²⁶ years (90% C.L.) with 3 years of livetime. Higher tellurium loading will follow for predicted sensitivities above 10²⁷ years (3% loading). In this seminar I will give a general introduction to the SNO+ experiment, present the latest results of our physics analyses, and discuss the prospects for the neutrinoless double-beta decay searches.