i was thinking about propagators, and I've got bit of a silly question.(adsbygoogle = window.adsbygoogle || []).push({});

The amplitude for any given decay takes the form:

[tex]f(q^{2})=\frac{g^{2}}{q^{2}+M_{X}^{2}c^{2}}[/tex].

for EMAG decays, the Mx=0 (as we're dealing with photons), so the amplitude is just:

[tex]f(q^{2})=\frac{g^{2}}{q^{2}}[/tex],

Why do we not consider the propagator: [tex]\frac{1}{q^{2}}[/tex] when determining decay rates (we just say its proportional to the fine structure constant to power of the number of vertices)?

**Physics Forums | Science Articles, Homework Help, Discussion**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Thinking about propagators

Loading...

Similar Threads for Thinking propagators |
---|

A Feynman integral with three propagators |

A QED propagator in Coulomb gauge |

I Dirac vs KG propagation amplitude |

I Klein-Gordon propagator |

I Klein Gordon propagator |

**Physics Forums | Science Articles, Homework Help, Discussion**