Perturbativity and a Fourth Generation in the MSSM

Abstract

We study an extension of the MSSM with a fourth generation of chiral matter. With this extension no value of $\text{tb}$ allows the theory to stay perturbative up to the GUT scale. We suggest one model with extra vector-like states at the TeV scale that allows perturbativity all the way up to the GUT scale.

Comments: 12 pages, 4 figures