The Quasi-Infra-Red Fixed Point at Higher Loops
P. M. Ferreira, I. Jack, D. R. T. Jones
Abstract
We calculate the four-loop $β$-function for the generalised Wess-Zumino model. We use the result and Padé-Borel summation to discuss the domain of attraction of the quasi-infra-red fixed point of the top-quark Yukawa coupling in the supersymmetric standard model, and argue that the domain is in fact substantial.