1
vote
1answer
513 views

Yukawa Coupling of a Scalar $SU(2)$ Triplet to a Left-Handed Fermionic $SU(2)$ Doublet

Suppose we have a field theory with a single complex scalar field $\phi$ and a single Dirac Fermion $\psi$, both massless. Let us write $\psi _L=\frac{1}{2}(1-\gamma ^5)\psi$. Then, the Yukawa ...
3
votes
2answers
427 views

How does non-Abelian gauge symmetry imply the quantization of the corresponding charges?

I read an unjustified treatment in a book, saying that in QED charge an not quantized by the gauge symmetry principle (which totally clear for me: Q the generator of $U(1)$ can be anything in ...
6
votes
1answer
407 views

Modes of a QFT and irreducible representation of the gauge group

This is in reference to the calculation in section 3.3 starting page 20 of this paper. I came across an argument which seems to say that the "constraint of Gauss's law" enforces gauge theory on ...