I am a bit confused about resonances in QFT. I am reading Schwarz's QFT book and as far as I understand, if in a reaction the mass of the particle acting as a propagator is bigger than the sum of the masses of the particles interacting, the propagator particle can be on shell, thus the propagator has an imaginary part and doing some math you get the Breit-Winger distribution (this is chapter 24.1.4). However, the particles that were discovered as resonances are not propagators, as far as I understand. For example, in muon-muon scattering to obtain the J/psi particle, the 2 muons interact by exchanging a photon, not a J/psi particle. So the propagator is that corresponding to a photon. Can someone explain to me how does this work? How do resonances from and how does this on-shell propagator comes into play? Thank you!
Subscribe to:
Post Comments (Atom)
-
Why can't we use fissions products for electricity production ? As far has I know fissions products from current nuclear power plants cr...
-
I have searched for equations regarding craters and I came across two of them. The first one is from this NOAO website in the level two sec...
-
As the title says. It is common sense that sharp things cut, but how do they work at the atomical level? Answer For organic matter, such a...
-
How can we know the order of a Feynman diagram just from the pictorial representation? Is it the number of vertices divided by 2? For exampl...
-
Yesterday, I understood what it means to say that the moon is constantly falling (from a lecture by Richard Feynman ). In the picture below ...
-
Literature states neutral pion decay by QED cannot occur directly because the pion is uncharged. However, I cannot see why Photons are not a...
-
This image from NASA illustrates drag coefficients for several shapes: It is generally accepted that some variation of the teardrop/airfoil...
No comments:
Post a Comment