2007/01/25 by Fleischer, Robert
#FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.hep-ph/0701217
We discuss the theoretical interpretation of the B→πK system in the light of new data. Using the branching ratio and direct CP asymmetry of B0d→π-K+, the picture of the direct CP violation in Bd0→π+π- could be clarified: we predict ACPdir(Bd→π+π-)=-0.24±0.04, which favours the BaBar measurement, and extract γ=(70.0+3.8-4.3)^∘, in agreement with the Standard-Model fits of the unitarity triangle. All B→πK modes with colour-suppressed electroweak penguin contributions are found in excellent agreement with the Standard Model. The data for the ratios Rc,n of the charged and neutral B→πK branching ratios, which are sizeably affected by electroweak penguin contributions, have moved quite a bit towards the Standard-Model predictions, which are almost unchanged, thereby reducing the "B→πK puzzle". On the other hand, the mixing-induced CP violation of B0d→π0 KS still looks puzzling and could be accommodated through a modified electroweak penguin sector with a large CP-violating new-physics phase, while the observed non-vanishing difference between the direct CP asymmetries of B^±→π0K^± and Bd→π^∓ K^± seems to be caused by hadronic and not by new physics.