The question says it all. Is there the theoretical possibility that one of the neutrino mass eigenstates have zero mass, whereas the other two have not? Is there a theory that allows this option? I seem to remember that this would mean that the zero mass neutrino state has always only one helic...

I understand that we can apply the Schrödinger equation to any wavefunction. Now, my question is, can we apply it to states that are being operated upon? Because, when we apply an operator on a state, we get another state which might/might not be a linear multiple of the original one, but still s...

Laser is built on quantum mechanics to create beam of photons with the same frequency and phase, then someone told me free electron laser is classical electrodynamics... is it true?

As far as I’m aware, our understanding of the strong interaction and strong nuclear force is pretty good. We can explain how particles move and stick together with good models. But from what I can find, I gather we do not have a mathematical theory that explains this in a precise manner. For exam...