Suppose that a tau neutrino and a tau antineutrino, both of which are just barely moving, encounter each other in space and completely annihilate to form two photons of equal energy.
In view of the uncertainty about the mass of the tau neutrino (< 18.2MeV/c²), what is the shortest wavelength λ₀ of light that could be emitted by the annihilation?
λ₀ =_____m
Would the light be visible to the human eye?
- No
- Yes