Analysis of the Decays B-> \pi \pi and \pi K with QCD Factorization in   the Heavy Quark Limit
  In this work, we calculate the branching ratios and CP asymmetries of the decays of $B \to \pi \pi$ and $\pi K$ in the frame of QCD factorization in the heavy quark limit. We also compare the results with the estimates by using conventional factorization and experimental measurements. 
Du Dongsheng, Yang Deshan and Zhu Guohuai