Model independent bound on the unitarity triangle from CP violation in B→π+π- and B→ψKS -: art. no. 021801

We derive model-independent lower bounds on the CKM parameters (1-(rho) over bar) and (eta) over bar as functions of the mixing-induced CP asymmetry S in B-->pi(+)pi(-) and sin2beta from B-->psiK(S). The bounds do not depend on specific results of theoretical calculations for the penguin contribution to B-->pi(+)pi(-). They require only the very conservative condition that a hadronic phase, which vanishes in the heavy-quark limit, does not exceed 90degrees in magnitude. The bounds are effective if -sin2betaless than or equal toSless than or equal to1. Dynamical calculations indicate that the limits on (rho) over bar and (eta) over bar are close to their actual values.