# A Dimension-5 interaction beyond the standard model

1. Apr 9, 2017

### spaghetti3451

Consider the following dimension-5 interaction:

$$\bar{\psi}D^{2}\psi.$$

Why is this interaction not consistent with either Lorentz invariance, the standard model field content or gauge invariance?

2. Apr 14, 2017

### PF_Help_Bot

Thanks for the thread! This is an automated courtesy bump. Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post? The more details the better.