Neutrinos have mass. Therefore, they can vary in speed. It is hard to measure speed exactly, but they travel very close to c. Higgs field model presumably covers their mass as well as for anything else.
According to the standard model, a neutrino can travel at any speed lower than c. Because their mass is so small, at normal energies they travel at very close to c.
#4
Severian
118
0
In the Standard Model, the neutrino can gain a mass from the Higgs field just as the other particles do. However with just this, it is difficult to explain why their masses are so small. A better idea is to give them a Majorana mass term, which naturally leads to small nuetrino masses via the see-saw mechnism.
#5
croghan27
58
0
How does this apply to a photon? They have no mass (presumably unsullied by the Higgs) but have momentum.
Is this a "now you have it, now you don't, moment"?