Charmless B⃗PP decays using flavor SU(3) symmetry

The decays of B mesons to a pair of charmless pseudoscalar (P) mesons are analyzed within a framework of flavor SU(3). Symmetry breaking is taken into account in tree (T) amplitudes through ratios of decay constants; exact SU(3) is assumed elsewhere. Acceptable fits to B⃗ππ and B⃗Kπ branching ratios and CP asymmetries are obtained with tree, color-suppressed (C), penguin (P), and electroweak penguin (P_EW) amplitudes. Crucial additional terms for describing processes involving η and η^′ include a large flavor-singlet penguin amplitude (S) as proposed earlier and a penguin amplitude P_tu associated with intermediate t and u quarks. For the B⁺→π⁺η^′ mode a term S_tu associated with intermediate t and u quarks also may be needed. Values of the weak phase γ are obtained consistent with an earlier analysis of B⃗VP decays, where V denotes a vector meson, and with other analyses of CKM parameters.