A low $α_s$ and its consequences for unified model building

Abstract

We review various ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of $α_s \sim 0.112$ indicated by several low energy experiments. We argue that to reconcile the low value of $α_s$ with the predictions of supersymmetric GUTs, we need to go beyond the standard minimal supersymmetric GUT scenario and invoke new physics either at $10^{11}-10^{12}$ GeV, or at the GUT scale.