pseudoscalar Yukawa interaction

[Guest]

Dear Florian,

I have a model with a Dirac field \Chi which is coupled to a pseudo-scalar
\phi as
L = g \phi \Chi \gamma^5 \chi
(g is a Yukawa coupling).
I have trouble with defining the Lagrangian in the model file.
(I would like to define a Dirac fermion and then defining the interaction
Lagrangian which has a Gamma^5 in it).

Would appreciate it if you help us with this problem

Best regards,

[FStaub]

Hi,

it's not possible to define the Potential terms using Dirac fermions. You need to use Weyl notation. To see how your concrete cases works, take a look at the model SM+VL/CPoddS where a CP-odd singlet is coupled to vectorlike fermions.

Cheers,
Florian