Grant: Subatomic Physics Envelope - Project

SNO+ is the follow-up experiment to the Sudbury Neutrino Observatory (SNO). Liquid scintillator will replace the heavy water that was in the SNO detector. By doing so, a new experiment with extended sensitivity at lower energies will be realized. SNO+ will be able to address fundamental questions in particle physics, in geosciences, and in astrophysics. SNO+ will start where SNO left off and will expand our understanding of the neutrino and its impact on the evolution of the Universe. A liquid scintillator emits over 50 times more light when a neutrino interacts in it compared to in water. Consequently SNO+ will be able to detect neutrinos with lower energies than SNO. Lower energy neutrinos from the Sun will be studied to shed light on the properties of neutrinos and the energy generation processes in stars. Separately, geo neutrinos from natural radioactivity in the Earth will be detected by SNO+. The quantity of geo neutrinos detected can be related to the total amount of radioactivity in the deep Earth and its role in Earth's thermal processes and history. Antineutrinos from nearby nuclear power reactors will be used to measure the parameters that govern the phenomenon of neutrino oscillations. Finally, an extremely rare nuclear decay will also be studied in SNO+ by dispersing tellurium in the liquid scintillator. Observation of this process, known as neutrinoless double beta decay (of 130 Te), would tell physicists about the matter-antimatter properties of the neutrino, and its connection to cosmological questions about matter and antimatter in the Universe. Fundamental symmetries and a connection to physics at higher energy scales are also both related to double beta decay. Hence, the experimental search for neutrinoless double beta decay is considered one of the most important pursuits in nuclear and particle physics today. SNO+ is transitioning to the commissioning, operations and data taking phase of the project. In late 2016, the detector will be completely filled with water. Data from water-filled SNO+ will be used to study detector optics and backgrounds, and to complete electronics/data acquisition commissioning. The commissioning of the scintillator purification plant will be taking place concurrently. In mid 2017, the scintillator plant and the SNO+ detector will be ready to receive and purify liquid scintillator. There will be a strong Canadian analysis effort that will extract physics results from the first SNO+ data. This proposal requests funds to support: HQP, travel, and materials and supplies related to SNO+ commissioning, data taking, tellurium liquid scintillator materials processing, and early physics studies. In addition, funds to support SNO+ operations at site (e.g. Detector Manager, assay technicians, plant operators) are required and are being requested.