Note that the neutrino masses are known to be non-zero because of neutrino oscillation, but their masses are sufficiently light that they have not been measured directly as of 2007. The names "mu" and "tau" seem to have been selected due to their places in the Greek alphabet; mu is seven letters after epsilon (electron), whereas tau is seven letter after mu.
- Particle physics
- Subatomic particle
- ↑ Rosenfeld, Léon (1948). Nuclear Forces. Interscience Publishers, New York, xvii.
- ↑ 2.0 2.1 2.2 Laboratory measurements and limits for neutrino properties.
- Griffiths, David J. 1987. Introduction to Elementary Particles. New York: Wiley. ISBN 0-471-60386-4
- Halzen, Francis, and Alan D. Martin. 1984. Quarks and Leptons: An Introductory Course in Modern Particle Physics. New York: Wiley. ISBN 0471887412
- Povh, Bogdan. 1995. Particles and Nuclei: An Introduction to the Physical Concepts. Berlin: Springer-Verlag. ISBN 0-387-59439-6