- #1
fliptomato
- 78
- 0
Hi everyone--I'm curious why terms in the Lagrangian with mass dimension greater than four are "nonrenormalizable."
I understand that the action must be dimensionless, hence the Lagrangian [density] has mass dimension 4. However, in effective field theories, we can end up with terms of dimension > 4, hence the coupling must have negative dimension. What's so bad about this?
(I guess somehow the renormalization group flow for such coupling constants diverges a mass scale given by the coupling?)
Thanks,
Flip
I understand that the action must be dimensionless, hence the Lagrangian [density] has mass dimension 4. However, in effective field theories, we can end up with terms of dimension > 4, hence the coupling must have negative dimension. What's so bad about this?
(I guess somehow the renormalization group flow for such coupling constants diverges a mass scale given by the coupling?)
Thanks,
Flip