Abstract
Using the Vlasov equation, we show that massive galactic halos cannot be composed of stable neutral leptons of mass ≲ 1 MeV. Since most of the mass in clusters of galaxies probably consists of stripped halos, we conclude that the "missing mass" in clusters does not consist of leptons of mass ≲ 1 MeV (e.g., muon or electron neutrinos). Lee and Weinberg's hypothetical heavy leptons (mass ≲ 1 GeV) are not ruled out by this argument.
- Received 31 May 1978
DOI:https://doi.org/10.1103/PhysRevLett.42.407
©1979 American Physical Society
