Speaker
Dr
Shigeki Matsumoto
(Kavli IPMU)
Description
Dark matter with sub-eV masses has an extremely high number density in our Galaxy, and its scattering with macroscopic objects can be significantly enhanced by coherence effects. Repeated scatterings with a target object can then induce a measurable acceleration. Torsion balance experiments with geometrically asymmetric test masses are, in principle, sensitive to such a signal. We show that existing torsion balance experiments originally designed to test the Equivalence Principle already provide the strongest constraints on dark-matter–nucleon scattering in the mass range 10^{-2}--1 eV.