ΛN spin-orbit splittings in _Λ⁹Be and _Λ¹³C studied with one-boson-exchange ΛN interactions

The relation of the splittings of the spin-doublet states in _Λ⁹Be and _Λ¹³C to the underlying antisymmetric spin-orbit (ALS) and LS forces was studied by using all available versions of the Nijmegen one-boson-exchange (OBE) models and taking the quark-model interaction properties into account. It was found that the NSC97f potential that uniquely reproduces the _Λ³H binding energy gives a larger spin-orbit splitting than the empirical value known so far. On the other hand, NSC97a and NSC97b potentials gave smaller values consistently within the experimental error. Further, the use of information on a quark-model ΛN potentials led to a far smaller spin-orbit splitting due to the large ALS force as to cancel most of the LS force.