A HΛ4+n+n model of HΛ6

A three-body calculation for the HeΛ6 and HΛ6 hypernuclei, in which the respective cores are He4 and HΛ4, has been initiated. The interactions in the HeΛ6 system are reasonably well known. For example, the Λn interaction is approximately determined by bubble-chamber Λ-p scattering data, the He4-Λ interaction can be fitted to the HeΛ5 binding energy, and the He4-n interaction can be fitted to α-n scattering data. For He4-n the s-wave can be modeled alternatively as a repulsive potential (Eskandarian and Afnan, 1992 [1]) or as an attractive potential with a forbidden bound state (Lehman, 1982 [2]). We examine the effect of these alternatives on He6 and Li6, because the interaction comes into play in modeling HeΛ6 as well as in our HΛ4+n+n model of HΛ6, where the valence neutrons are Pauli blocked from the s-shell of the core.