Constraints on the form factors for K --> pi l nu and implications for V_us
Abstract
Description
Rigorous bounds are established for the expansion coefficients governing the shape of semileptonic K-->pi form factors. The constraints enforced by experimental data from tau-->K pi nu eliminate uncertainties associated with model parameterizations in the determination of |V_us|. The results support the validity of a powerful expansion that can be applied to other semileptonic transitions.
5 pages, 3 figures; references added, version to appear in Phys. Rev. D alongside hep-ex/0608058
5 pages, 3 figures; references added, version to appear in Phys. Rev. D alongside hep-ex/0608058