Astrophysics and cosmology present a number of questions that may require physics beyond the Standard Model. Chief among these is the presence of nonluminous dark matter, which explains the rotation of galaxies and the motions of galaxies within clusters.
In the 1980's particle astrophysicists realized that a popular extension of the Standard Model known as Supersymmetry predicted the existence of a particle that might well be the dark matter. At the same time, a theory proposing an inflationary universe provided an attractive explanation for the primordial fluctuations that seeded cosmic structure, the imprint of which is seen in the anisotropy of the cosmic microwave background. These collaborative efforts of particle physicists and astrophysicists led to the Cold Dark Matter (CDM) paradigm that is firmly established as the leading scenario to explain the structure of the Universe from galactic to cosmological scales. Our current understanding is that 84% of the matter in the universe today is comprised of this completely unknown form of dark matter.
Searches for dark matter are a prominent part of the Canadian research program, and extracting results from current experiments while developing the technology for even more sensitive future detectors is a research priority of Queen’s University and its collaborators. As the nature of dark matter is largely unknown, a diverse program exploring a wide range of masses and with sensitivity to a variety of nuclear response functions is required. Hence, several experiments with different capabilities are currently underway or planned for SNOLAB.