Dark matter: The hunt for the unknown

Despite all of our advancements in science, physics, and astronomy, we still try to understand what approximately 80%-90% of the content of the Universe is. However, astronomical and cosmological observations strongly suggest the presence of a new form of matter different from the ordinary matter that surrounds us and which would be five times more abundant named “Dark Matter”. The only visible effects of its existence are its gravitational influence on ordinary matter composing galaxies but it may be detectable in particle physics experiments. At present, it is still invisible and undetectable directly. This makes it one of the greatest unsolved mysteries of our universe. Does it exist or not? Do we need to change our theories and create new ones? Even if its direct detection escaped the scientific community in our time, dark matter remains a fundamental concept that would explain how our Universe formed and would provide a unique chance to discover physics beyond the standard model. Currently many experiments around the world are searching for dark matter and we hope that in the near future we will solve this mystery and understand its properties. After reviewing in detail why dark matter matters and the strong evidence of its existence, I will give an overview of the numerous direct dark matter searches with emphasis in our involvement in Canada and the challenge we are now facing by reaching such unprecedented level of sensitivity that never-before-seen background signals must be now considered.

Marie-Cécile Piro is a french-italo-canadian who grew up in a tiny french island in the Caribbean the Guadeloupe. She moved to Montreal for her undergraduate and graduate studies at Université de Montréal and received her PhD in 2012 in experimental particle physics in the PICASSO collaboration using superheated liquid detectors for the search of dark matter. She continued her quest for dark matter as a postdoctoral associate in France within the EDELWEISS group working with High Purity Germanium (HPGe) bolometer. She moved in US to work as a research associate with the XENON1T experiment and spent two years in Gran Sasso in Italy for the complete commissioning of the detector, as expert on-site of the purification system and slow control for the experiment. Since 2017, Marie-Cécile has been an Assistant professor at the University of Alberta in Edmonton, and she continues her research as a leader in the dark matter searches within several experiments in gas purification to reduce the background level of the detectors and data analysis to understand the behavior of the detectors. She is very involved in the scientific community and outreach activities for inspiring young people, and will continue it by being the chair of the particle physics division of the Canadian Association of Physicists (CAP).