K* resonance effects on direct CP violation in B→ππK

B±→π+π-K± and B0→π+π-K0 decay channels are analyzed within the QCD factorization scheme where final state interactions before and after hadronization are included. The K*(892) and K0*(1430) resonance effects are taken into account using the presently known πK strange vector and scalar form factors. The weak decay amplitudes, which are calculated at leading power in ΛQCD/mb and at the next-to-leading order in the strong coupling constant, include the hard-scattering and annihilation contributions. The end-point divergences of these weak final state interactions are controlled by two complex parameters determined through a fit to the available effective mass and helicity angle distribution, CP asymmetry, and K*(892) branching ratio data. The predicted K0*(1430) branching ratios and the calculated direct CP violation asymmetries are compared to the Belle and BABAR Collaboration data.