Determining the weak phase γ using the decays Bd, B+→Kη(η′) and Bs→πη(η′)

We suggest two methods (based on flavor SU(3) symmetry) to determine the CKM angle γ using the decays Bd, B+→Kη(η′) and Bs→πη(η′), respectively. Rescattering effects are partly included – we neglect annihilation amplitudes, but do not assume any other relation between the SU(3) invariant amplitudes. We use the fact that the amplitude (including the Electroweak Penguin contribution) for Bd, B+→πK with final state I(isospin)=3/2 is known as a function of γ from the decay rate B+→π0π+.