Calculation of the binding energy and of the parameters of low-energy scattering in the Lambda np system

The cluster-reduction method is used to solve the differential Faddeev equa tions for S = 1/2, T = 0 and S = 3/2, T= 0 spin-isospin states of the Lambd a np system in the s-wave approximation. The NN interaction is simulated on the basis of the MT I-III potential model, and the Lambda N potential is s et to V-Lambda N = V-NN/2. This simple option makes it possible to reproduc e faithfully the binding energy of the hypertriton H-3(Lambda). The doublet and quadruplet Lambda d scattering lengths and the low-energy phase shifts are calculated. It is shown that the effective-range approximation is appl icable to the cases of doublet and quadruplet scattering. (C) 2000 MAIK "Na uka/lnterpeniodica".