Possible large directCPviolations in charmlessBmeson decays: Summary report on the PQCD method

We discuss the perturbative QCD approach for the exclusive two body B meson decays to light mesons. We briefly review its ingredients and some important theoretical issues on the factorization approach. We show numerical results which are compatible with present experimental data for charmless B meson decays. In particular, we predict the possibility of large direct $\mathrm{CP}$ violation effects in $B^0\to {\pi }^{+}{\pi }^{-}\left[\right(23\mathrm{}\pm 7\%\left)\right]$ and $B^0\to K^{+}{\pi }^{-}\left[\right(-17\pm 5\%\left)\right].$ In the last section we investigate two methods to determine the weak phases ${\phi }_2$ and ${\phi }_3$ from $\overrightarrow{B}\pi \pi ,K\pi$ processes. We obtain bounds on ${\phi }_2$ and ${\phi }_3$ from present experimental measurements.