Title: Digginginto Mysteries: the Search for Dark Matter at SNOLAB
Speaker: Dr. Pierre Gorel
Description: Ourunderstanding of the laws of physics has been going by leaps and bonds in thelast century. The Standard Model of Particle Physics has been very successful,culminating with the discovery of the previously predicted Higgs boson. Andyet… it is enough to look up and survey the sky to discover that this greatachievement explains less than 5% of the Universe. Many clues point to theexistence of five times more matter with no electromagnetic interaction, makingit impossible to observe except for its effect on the gravity field. The mostfavored candidates for this “dark matter” are the Weakly Interacting MassiveParticles (WIMPs). They would scatter off nuclei, producing detectable recoils.Over the last decades, a word-wide effort has taken to look for theseparticles, which have managed so far to stay elusive. As a results, thedetectors have become bigger and bigger, reaching new levels of sensitivity.The corollary is that the “low background” requirement inherent to this kind ofdetector became more and more stringent, forcing experiment to be built withthe thickest overburden possible to be protected against cosmic rays. In thislandscape, SNOLAB is one of the best laboratories in the world. With more than2 km of rock overburden in the heart of the Canadian Shield, the facility hasbeen built on the success of the SNO experiment (Nobel prize cowinner 2015) andis dedicated to low background research. With 6 projects at various stages ofreadiness and operation, direct dark matter search occupies a place of choicein the physics program of SNOLAB, next to neutrino detection and biology. Inthis talk, I will discuss the recent results published by three of them.