Neutrinos may have mass Dipayankar; Neutrino Mass?
No definite mass has been measured for the
neutrino, and the standard comment about most experiments is "the results are consistent with zero mass for the neutrino". But this raises certain theoretical problems and there have been many attempts to set a range for the mass of the neutrino. Since its mass is evidently very small, if non-zero, the mass is usually stated in terms of its
energy equivalent in
electron volts. Most experiments conclude that the mass equivalent of the neutrino is less than 50 eV.
For the most part they were created at the "Big Bang" though they are created today from nuclear reactions. Best, Pat