A New Mechanism for $B^{\pm}\to η'K^{\pm}$ in Perturbative QCD

We present a new mechanism for $B^{\pm}\to \eta' K^{\pm}$, and analyze it strictly within perturbative QCD. We find that such a new mechanism may dominate non-leptonic $B$-decays to light mesons. Within a reasonable parameter space, our prediction is in good agreement with the recent CLEO data on $B^{\pm}\to \eta' K^{\pm}$. We conclude that there is no room for an abnormally large \bsg vertex from physics beyond the Standard Model.