All Questions
4 questions
0votes
1answer
77views
Simplify a vertex in the on-shell form
I am calculating with a vertex connecting a pion, delta and a nucleon. In general, the vertex is calculated as $$ \Gamma_{\pi N \Delta, a}^{\mu} \sim \gamma^{\mu\nu\rho} (p_\pi)_{\nu}(p_\Delta)_\rho ...
- 55
3votes
2answers
431views
Renormalization and virtual soft divergences
I am reading Weinberg's book on QFT. Specifically, chapter 13.2. The author calculates the effect of including infrared quantum corrections (i.e. associated with soft virtual photons) to amplitudes. ...
- 4,253
2votes
0answers
304views
On-shell propagator to an off-shell propagator
I am learning the Ward-Takahashi Identity part of Peskin and Schroeder's textbook of quantum field theory. In the prove process, it involves a diagram 7.66. Then it says that I can understand ...
- 576
2votes
0answers
346views
LSZ reduction formula for massive vector bosons
What is the precise form of the LSZ reduction formula for massive vector bosons? The LSZ formula for scalar bosons, fermions, and photons is given e.g. in the textbook "Quantum field theory" by ...
- 2,339
