Fat penguins and imaginary penguins in perturbative QCD

We evaluate B --> K pi decay amplitudes in perturbative QCD picture. It is found that penguin contributions are dynamically enhanced by nearly 50% compared to those assumed in the factorization approximation. It is also shown that annihilation diagrams are not negligible, and give large strong phases. Our results for branching ratios of B --> K pi decays for a representative parameter set an consistent with data. (C) 2001 Published by Elsevier Science B.V.