Neutrino

:Neutrino is also an operating system. See QNX.

Mass

The Standard Model of particle physics assumes that neutrinos are massless, although adding massive neutrinos to the basic framework is not difficult. Indeed, the experimentally established phenomenon of neutrino oscillation requires non-zero neutrino masses. The strongest upper limits on neutrino mass come from cosmology. The Big Bang model predicts that there is a fixed ratio between the number of neutrinos and the number of photons in the cosmic microwave background. If the total mass of all three types of neutrinos exceeded 50 electron volts (per neutrino), there would be so much mass in the universe that it would collapse. This limit can be circumvented by assuming that the neutrino is unstable; however, there are limits within the Standard Model that make this difficult.

Related Topics:
Neutrino oscillation - Cosmology - Big Bang - Photon - Cosmic microwave background - Electron volt

~ ~ ~ ~ ~ ~ ~ ~ ~ ~