I'm dealing with a doubly charged scalar singlet that interacts only with the right-handed muon as follows,

$$\mathcal{L} = \lambda \psi_{R}C\psi_{R} \phi^{++},$$

where $\lambda$ is the coupling, $\psi_{R}$ is the right-handed muon, $C$ is the charge conjugation matrix in some representation and $\phi^{++}$ is the doubly charged scalar singlet. My question is, how to extract Feyman's rules from this? More precisely, the vertex.

My first thought was: $i\lambda \frac{1}{2}(1+\gamma_{5})$C, but when I think about fermions interacting with a scalar I'm supposing something like $\mathcal{L} = \lambda \overline{\psi}\psi\phi$, from where the vertex is $i\lambda$. But I don't have an adjoint $\overline{\psi}$, and I have no idea how the charge conjugation will get in the vertex expression.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.