# Help -- Writing Lagrangian in different Representations

1. Oct 12, 2014

### Karatechop250

Okay, so I am trying to understand on how to write Lagrangian in different representations. I know the formula of the SU(3) lagrangian in terms of the 3 and 3* rep. Now presume I have a model in the SU(3) 10 plet rep which includes exotic fermions not in the SM. How would I write out the lagrangian for this new model ? Does anyone know of any sources on writing lagrangians in different representations.

2. Oct 17, 2014

### Greg Bernhardt

$$\mathcal{ L } = i \bar{ [ 10 ] } \gamma^{ \mu } \partial_{ \mu } [ 10 ]$$