Abstract
The present cosmic mass density of possible stable neutral heavy leptons is calculated in a standard cosmological model. In order for this density not to exceed the upper limit of 2× g/, the lepton mass would have to be greater than a lower bound of the order of 2 GeV.
- Received 13 May 1977
DOI:https://doi.org/10.1103/PhysRevLett.39.165
©1977 American Physical Society