A low $\alpha_{s}$ and its consequences for unified model building

摘要

We review various ways of obtaining consistency between the idea of supersymmetric grand unification and an apparent low value of \alpha_s \sim 0.112 indicated by several low energy experiments. We argue that to reconcile the low value of \alpha_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.