Recent content by fpa2011

the physical states are the mass states I think. As for the Feynman diagrams, I think they use the physical/mass states too because I can't remember ever drawing or seeing a diagram where there's been interaction states on it. they are always made with, say, an electron e rather than using the...

are you sheffield uni by any chance? I've just asked this question in another section. also your answer is what I heard yesterday.

what is the difference between a "mass state" and an "interaction state"? I've encountered these terms a few times with no explanation, and googling around turns up absolutely nothing. Can anyone give me a brief description of the two terms, suitable for undergraduate level? thanks.