Mean-field approach to Λ and Σ hypernuclei

The Lambda -nucleus and the Sigma -nucleus potentials are compared in the relativistic, zero-range mean-field model. The authors find the relative strength of the spin-orbit interaction RSigma Lambda =VLSSigma /VLSLambda to be particularly sensitive to the various model assumptions; an experimental ratio RSigma Lambda approximately=1 would support strong SU(3) symmetry breaking as the major source for a small spin-orbit interaction in hypernuclei, whereas a ratio RSigma Lambda >>1 supports predictions based on a good SU(3) symmetry in combination with a large tensor coupling of the omega meson and from the quark model.