K* resonance effects on direct CP violation in B -> pi pi K

TL;DR

This paper investigates how K* resonance effects influence direct CP violation in B meson decays to pi pi K final states, using QCD factorization with resonance form factors and fitting parameters to experimental data.

Contribution

It introduces a detailed analysis of K* resonance effects in B decays within QCD factorization, incorporating form factors and fitting parameters to experimental observables.

Findings

Predicted K*(1430) branching ratios agree with data.

Calculated direct CP asymmetries match experimental measurements.

Resonance effects significantly impact CP violation in B decays.

Abstract

Charged and neutral B decays into two charged pions and a charged or a neutral kaon are analyzed within the QCD factorization scheme where final state interactions before and after hadronization are included. The K*(892) and K*(1430) resonance effects are taken into account using the presently known pion-Kaon strange vector and scalar form factors. The weak decay amplitudes, which are calculated at leading power in Lambda_QCD/m_b 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 K*(1430) branching ratios and the calculated direct CP violation asymmetries are compared to the Belle and BABAR Collaboration data.