CP Violation and Nonleptonic B-meson Decays

We discuss the perturbative QCD approach for exclusive non-leptonic two body B-meson decays. We briefly review its ingredients and some important theoretical issues related to the factorization approach. PQCD results are compatible with present experimental data for the charmless B-meson decays. We predict the possibility of large direct CP violation effects in $B^0 \to \pi^{+}\pi^{-}$ $(23\pm 7$ and $B^0\to K^{+}{\pi }^{-}$ $(-17\pm 5$. For charmed decay $B\to D^{(\ast )}\pi$, we get large non-factorizable contributions for Color-suppressed decays and obtain $\mathrm{\mid }{a}_2\mathrm{/}{a}_1\mathrm{\mid }\sim 0.4-0.5$ and $Arg(a_2\mathrm{/}{a}_1)\sim -{42}^o$. In the last section we investigate the method to extract the weak phases ${\varphi }_2$ from $B\to \pi \pi$ decay and ${\varphi }_3$ from $K\pi$ modes. From BaBar measurement of CP asymmetry for the ${\pi }^{+}{\pi }^{-}$ decay, the prefered CKM weak phases are: ${\varphi }_1=(24\pm 2{)}^o$, $\phi_2=(78\pm 22)^{o}$and$\phi_3=(78\pm 22)^{o}$.