What is the difference(or relation) between Yukawa interaction($\mu\bar{\psi}\phi\psi$) and the other four fundamental interactions(e.m., weak, strong and gravity)? Does it fall anywhere on the symmetry breaking scale starting from Big bang?
How to understand Yukawa interaction with parallel to the other four forces? Now that Quantum Chromodynamics (QCD) is the theory that describes the interactions inside a nucleus, my understanding is: Yukawa theory was developed much before the advent of gauge theories to explain the nuclear interactions. So, is Yukawa theory redundant or obsolete? I know that Yukawa interaction now is used in Standard Model to describe the interaction between massless fermions and scalar Higgs boson.


closed as unclear what you're asking by John Rennie, ACuriousMind, mpv, Qmechanic Feb 29 '16 at 12:25

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    $\begingroup$ Yukawa is not a gauge force, for a start. $\endgroup$ – Slereah Feb 29 '16 at 9:34
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    $\begingroup$ I'm not sure what this question is asking for. A list of all the differences between a Yukawa interaction and a minimal gauge coupling would be too broad. Can you be more specific what you want to know? $\endgroup$ – ACuriousMind Feb 29 '16 at 10:26
  • $\begingroup$ I am trying to understand how Yukawa interaction differs from the other four forces. Slereah started by clearing that it is a non-gauge force; we use it in the Standard Model in the Spontaneous Symmetry Breaking. May be this is the best way to ask: can it be derived from the other four forces directly or as an approximation as it is not fundamental? $\endgroup$ – user31694 Mar 6 '16 at 7:50
  • $\begingroup$ Please reopen this post for better answering $\endgroup$ – user31694 Jan 18 '18 at 11:42