Penguins, trees and final state interactions in B decays in broken SU3

The availability of data on Bs decays to strange quasi-two-body final states, either with or without charmonium opens new possibilities for understanding different contributions of weak diagrams and in particular the relative contributions of tree and penguin diagrams. Corresponding Bd and Bs decays to charge conjugate final states are equal in the SU(3) symmetry limit and the dominant SU(3) breaking mechanism is given by ratios of CKM matrix elements. Final State Interactions effects should be small, because strong interactions conserve C and should tend to cancel in ratios between charge conjugate states. Particularly interesting implications of decays into final states containing η and η′ are discussed.