Improved method for CKM constraints in charmless three-body B and B-s decays

Recently Ciuchini, Pierini, and Silvestrini proposed a method for constraining CKM parameters in B -> K pi pi and B-s -> K pi pi through phase measurements of amplitudes involving I=3/2 K-*pi final states. We show that complementary information on CKM parameters may be obtained by studying the phases of Delta I=1 B ->(K-*pi)(I=1/2), B-s ->((KK)-K-*)(I=1) and B-s ->((KK)-K-*)(I=1) amplitudes. Hadronic uncertainties in these constraints from electroweak penguin operators O-9 and O-10, studied using flavor SU(3), are shown to be very small in B -> K pi pi and B-s -> K pi pi and somewhat larger in B-s -> KK pi. The first processes imply a precise linear relation between rho and eta, with a measurable slope and an intercept at eta=0 involving a theoretical error of 0.03. The decays B-s -> K pi pi permit a measurement of gamma involving a theoretical error below a degree. We note that while time-dependence is required when studying B-0 decays at the Upsilon(4S), it may not be needed when studying B-s decays at hadronic colliders.