# Callan-Symanzik equation in dimensionally regularized scheme

1. Jul 24, 2011

### metroplex021

In every textbook treatment of the CS equation for the bare theory I've seen, the CS equation (and hence the beta-function) is expressed (partly) in terms of variations with respect to the cut-off Lambda, where it is clear that this Lambda refers to a hard momentum cut-off. Can anybody direct me to an expression for the CS equation (for the bare theory) in which the cut-off is modelled by the epsilon of dimensional regularization, where epsilon =4-d, where d is the number of space dimensions? (It seems weird that (as I'm told) particle physicists almost always use dimensional regularization in their day-to-day work, and yet the textbook expos of the CS equation all seems to assume hard cut-off regularization.) Any help or hook-ups gratefully received!