The K-α scattering length and the reaction dd↦αK+K-

Abstract.We present predictions for the K-α scattering length obtained within the framework of the multiple-scattering approach. Evaluating the pole position of the K-α scattering amplitude within the zero-range approximation, we find a loosely bound K-α state with a binding energy of ER = - 2,..., - 7 MeV and a width ΓR = 11,..., 18 MeV. We propose to measure the K-α scattering length through the final-state interaction between the α and K--meson produced in the reaction dd↦αK+K-. It is found that the K-α invariant-mass distribution from this reaction at energies near the threshold provides a new tool to determine the s-wave K-α scattering length.