Ultracold Neutrons at TRIUMF

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Ultracold neutrons (UCN) are slow moving neutrons that can be stored in material, magnetic, and gravitational bottles. Once they've been confined using such methods, their properties can be studied very carefully to search for deviations from expectations based on the standard model of particle physics.We have nearly completed a new source of UCN in Canada (at TRIUMF, Vancouver, BC) with the help of collaborators from Japan (Masuda, et al.). The source is projected to provide the highest density of UCN in the world. The UCN we will produce will be used to advance fundamental physics experiments to unprecedented levels of precision.Initially we are focused on a measurement of the neutron electric dipole moment (nEDM), and it is primarily our activities on R&D for this experiment which require support from NSERC. A new measurement of the nEDM will place even tighter constraints on theories involving new sources of Charge-Parity (CP) violation beyond the standard model. It is believed these are required in order to explain the predominance of matter over antimatter (baryon asymmetry) in the universe today. Quite generically, it constrains broad classes of theories which may not conserve CP, for example supersymmetry. A new measurement will also further constrain a long-standing mystery in the standard model, involving the appararent lack of CP violation arising from the strong force. A discovery of a non-zero nEDM would obviously be a major discovery, since it could potentially shed light on such a broad range of theories.Our activities over the next three years will involve the completion of the UCN facility at TRIUMF, and the completion of key research and development that will enable a future world-leading neutron electric dipole moment experiment.