Breit-Wigner propagator Of resonance

1. Mar 20, 2015

zhangyang

Ｉ Want to analyze the decay from a excited nucleon to a nucleon and an Omega meson.I have seen a propagator

which descripes a process : a→b+c

(Eur. Phys. J. A16, 537–547 (2003), Covariant tensor formalism for partial-wave analyses ofψdecay to mesons ,B.S. Zou and D.V. Bugg)

But how could it be obtained? Is it general and universal?

Or ,how to construct a vertex of the process phenominologically?

Last edited: Mar 20, 2015
2. Mar 20, 2015

Einj

If you want to know exactly where the Breit-Wigner propagator comes from you can look at De Wit - Field Theory in Particle Physics, or Weinberg - Lectures on Quantim Mechanics, the chapter on resonance. The Breit-Wigner distribution (propagator), however, is not general nor universal. It is used to treat resonances and, if I remember correctly, should also contain some finite time corrections, but I'm not sure. However, they are very often ignored.

As far as the phenomenological vertex is concern, it strongly depends on your quantum numbers. What are the initial and final particles?