# Yukawa couplings

1. Jan 27, 2008

### Jim Kata

I don't know that much about GUT's, but am interested in them. My question is can they be used to explain the Yukawa coupling constants like $$G_e$$ which appear in terms like:
$$L_{\phi e} = - G_e \left( {\begin{array}{*{20}c} {\bar \upsilon _e } \\ {\bar e} \\ \end{array} } \right)_L \left( {\begin{array}{*{20}c} {\phi ^ + } \\ {\phi ^0 } \\ \end{array} } \right)e_R$$

If so, how does this work.

2. Jan 28, 2008

### kdv

My understanding is that GUT do no explain the Yukawa couplings in the sense of providing a deeper explanation but they *reduce* the number of independent Yukawa couplings because the particles are grouped in larger multiplets. So, for example, the Yukawa coupling of the quarks are related to those of the leptons of the same generation and so on.