Grant: Subatomic Physics Envelope - Project

Unlike the neutrons inside of the nucleus of an atom, Ultra Cold Neutrons (UCN) are free to move around, and they have interesting properties. UCN are trapped by Earth's gravitational field, they bounce off walls, and they can be stored in magnetic bottles. Since UCN can be stored for a long time, and many neutrons can be produced, properties of neutrons can be studies to high precision such as the neutron lifetime, and the neutron beta decay asymmetry. A motivation for producing a high intensity neutron source is that an observation of a permanent Electric Dipole Moment (EDM) of the neutron would imply new physics. An electric dipole moment is created when there are two charges separated from one another, and in the standard model, the neutron EDM is predicted to be ~1e-31 e cm. If neutrons are found to have a larger EDM, it will in part help explain the matter domination of the universe which is not accommodated by the standard model. To put the extraordinary degree of sensitivity to which we plan to measure the nEDM into a human perspective, if one imagines a neutron expanded to the size of the Earth, the current limits around 1e-26 e cm correspond to a separation of the centres of charge of about 1.5 microns. This proposal is to collaborate on a neutron EDM experiment being developed in Japan, that will eventually be moved to a new ultra cold neutron beamline being built at TRIUMF, in Vancouver. My role will be to lead the simulation of the experiment, and to develop neutron monitoring detectors. The TRIUMF UCN beam will be the most intense source in the world and enable other world leading experiments such as the neutron lifetime and decay asymmetry, hopefully leading to nobel prize winning discoveries.