Grant: Subatomic Physics Envelope - Project

Neutrons are usually bound inside the nucleus of the atom. When neutrons are taken out of atomic nuclei and cooled down, they have weird properties: they bounce off walls, they can be stored in magnetic bottles, and they are trapped by Earth's gravitational field. 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 ultracold neutrons (UCN) in Canada (at TRIUMF, Vancouver, BC) with the help of collaborators from Japan (Masuda, et al). The UCN source for TRIUMF was recently approved by funding agencies in both Canada and Japan. The source is projected to provide the highest density of UCN ever produced in the world, and we'll use the neutrons to push some very interesting physics experiments to unprecedented levels of precision: a measurement of the neutron electric dipole moment (nEDM), a measurement of the neutron lifetime, and a measurement of neutron energy levels in Earth's gravity. We intend eventually to develop all three experiments; we will focus initially on research and development for a measurement of the nEDM. Measurements of electric dipole moments already severely limit new sources of Charge-Parity (CP) violation beyond the standard model. If a non-zero value were discovered at the level of experimental precision of a new experiment, it would signify a new source of CP violation. Such a result would be so amazing that it would likely result in a Nobel Prize for the discoverer. With support from NSERC, we intend to continue our progress towards the development of this exciting experiment. This will focus on experiments using UCN produced at our prototype source in Japan. The experiments revolve around production, storage, polarization, and manipulation of the spins of the UCN, and will ultimately lead to a world-class experiment at TRIUMF.