Particle Physics Beyond Colliders

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The Standard Model successfully describes phenomena from subatomic to galactic scales and has been verified to the 10-12 level in some cases. Despite its immense success, the Standard Model is incomplete. The origin of the parameters in the theory, eg. the Higgs mass, are yet to be understood and the nature of the Dark Matter, which accounts for a huge part of the mass of the universe, remains a mystery. I have drawn together ideas from wide-ranging areas of physics to propose novel theoretical ideas addressing these longstanding problems, and to connect theory with experiments, and astrophysical observations complementary to collider searches. This approach is motivated both by advances in other fields of physics as well as theoretically. For example, in atom interferometry an atom can find itself in a superposition of quantum states separated by half a meter for about one second. Searches for electric dipole moments have also reached an unprecedented precision level; they can detect a charge asymmetry on the electron so small that, were the electron blown up to earth's size, it would correspond to determining the center of mass of the earth relative to the center of charge to a distance smaller than the size of the atom! Together with my students, my research program will seek novel ways in which these advances can be used to detect new forces as well as DM. In 2009, we showed that the complexity of string compactifications gives rise to a plenitude of particles that are extremely light and interact with the Standard Model weakly. This idea has grown into a new field and will involve major international experiments. These particles, if discovered, would be indirect evidence of such a structure, providing the best theoretical motivation behind new experiments at the so-called precision frontier. These experiments can probe Nature at a scale much smaller than colliders but with the same potential impact. A golden era of data for Particle Physics continues with astrophysics and gravitational wave astronomy. Advanced LIGO is the first experiment to detect gravitational waves. I showed that through the effect of Black Hole (BH) Superradiance, it can diagnose the presence of light bosons whose Compton wavelength is similar to that of astrophysical BHs and can be detected at LIGO. I intend to explore the full potential of this astrophysical probe. Finally, the extremely light particles motivated by string theory suggest a novel picture of Dark Matter with attractive self-interactions changing the small scale structure of the universe, and possibly providing another source of gravitational wave radiation at extremely low frequencies; astrophysical experiments looking for such signatures can shed new light on our search for DM. Given that the proposed experiments can give results in as little as five years, my program can quickly boost Canada's position as a world pioneer in fundamental physics while training a new generation of scientific leaders.