Measuring Cabibbo-Kobayashi-Maskawa parameters withCPasymmetry and isospin analysis inB→πK

Isospin relations are used to eliminate hadronic uncertainties in various CP asymmetries in ${\mathit{B}}^0$ decays via b→uu¯s, e.g., ${\mathit{B}}^0$→${\mathrm{\pi }}^0$ ${\mathit{K}}_{\mathit{S}}$. A clean measurement of the angle α of the unitarity triangle is thus made possible. The magnitudes of the tree and the penguin amplitudes can be measured.