Grant: Subatomic Physics Envelope - Project

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 are building 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 ever produced in the world, and the UCN we produce will be used to push some very interesting physics experiments to unprecedented levels of precision. Initially we are focused on a measurement of the neutron electric dipole moment, and it is primarily our activities on this experiment for which we are seeking NSERC support. Measurements of electric dipole moments already severely limit new sources of Charge-Parity (CP) violation beyond the standard model, sources which are believed to be required in order to explain the predominance of matter over antimatter (baryon asymmetry) in the universe today. If a non-zero value were discovered at the level of experimental precision within reach of our new experiment, it could signify a new source of CP violation, and hence help to explain the baryon asymmetry of the universe. Our activities over the next three years will involve the construction of equipment for ongoing experiments in Japan, the use of the equipment to complete initial EDM experiments in Japan, and the delivery of the EDM experiment back to TRIUMF for installation. As we learn through experiments in Japan, we will also develop new ideas for the best possible experiment at TRIUMF, and prepare the experimental area at TRIUMF. This will result in a world-leading experiment at TRIUMF.