Spin-orbit splitting in σ-hypernuclei

The shell model analysis of experimental 0+, 2+ spectra of\(_{\Sigma ^ - } {}^{12}Be\) and\(_{\Sigma ^ - } {}^{16}C\) as obtained from (K−,π+) in-flight and stoppedK− reactions, is performed. It suggests a large (twice that for nucleons) spin-orbit splitting of Σ hyperon levelsp3/2 andp1/2. Certain constraints on effective central ΣN interaction arise, as well. Some experiments are put forward to further test this value and to extend it to Ξ hypernuclei.