New physics in $B \to \pi \pi$ and $B \to \pi K$ decays

We perform a combined analysis of $B \to \pi \pi$ and $B \to \pi K$ decays with the current experimental data. Assuming SU(3) flavor symmetry and no new physics contributions to the topological amplitudes, we demonstrate that the conventional parametrization in the Standard Model (SM) does not describe the data very well, in contrast with a similar analysis based on the earlier data. It is also shown that the introduction of smaller amplitudes and reasonable SU(3) breaking parameters does not improve the fits much. Interpreting these puzzling behaviors in the SM as a new physics (NP) signal, we study various NP scenarios. We find that when a single NP amplitude dominates, the NP in the electroweak penguin sector is the most favorable. However, other NP solutions, such as NP residing in the QCD-penguin sector and color-suppressed electroweak penguin sector simultaneously, can also solve the puzzle.