Λ-neutron scattering lengths from radiative K^- capture

Radiative capture of the K^- by the deuteron is examined as a reaction for measurement of Λ-neutron scattering lengths. Using the final-state interaction, analogous to measurements of the radiative capture of pions by deuterium, the scattering lengths of both the triplet and singlet Λ-n interaction can be inferred. The problem of the separation of these two fundamental parameters without and with spin information in the experiment is addressed. It is shown that a measurement of the deviation of the vector deuteron polarization asymmetry from -1 provides a direct determination of the difference of the singlet and triplet scattering lengths.