Losing Dark Matter in the Fog? The Historical Arc of the WIMP Paradigm

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Abstract:
After almost four decades of searching for the hypothetical Weakly Interacting Massive Particles (WIMPs)—the long-favored candidate for the elusive dark matter, making up 85% of the mass in the universe—experiments have recently hit an awkward milestone. Two experiments aiming to observe WIMPs have detected the first hints of cosmic neutrinos. This achievement has long been dreaded by dark matter researchers: cosmic neutrinos act as an unremovable “fog” that obscures WIMPs entering the detector. As such, some say, this could well mean the end of the longstanding WIMP paradigm. In the face of this potential ending, I trace how the WIMP paradigm struck root in the first place. Following the entanglements between neutrino physics, particle theory, and cosmology in the late 1970s, I show how, in a strange irony of history, neutrinos were key to the success and establishment of the WIMP paradigm. These historical reflections, I argue, might help physicists turn potential endings into new beginnings.

Speaker Bio:
Jaco de Swart has been working at MIT since 2022 as an AIP Robert H. G. Helleman Postdoctoral Fellow, and this fall he will be taking up a Marie Skłodowska-Curie Actions postdoctoral fellowship at Cambridge University. Prior to his arrival at MIT, he received his PhD at the Institute of Physics at the University of Amsterdam and was a postdoctoral researcher at the Amsterdam School for Social Science Research. His research focuses on the history of dark matter, which is the subject of a book he is writing under contract with the MIT Press. De Swart also has a passion for science communication and appeared in a PBS NOVA documentary last year on dark energy and dark matter. He also practices his showmanship as a bassist in the band X Raiders.