S-shell $$\varLambda \varLambda $$ hypernuclei based on chiral interactions

We generalize the Jacobi no-core shell model (J-NCSM) to study double-strangeness hypernuclei. All particle conversions in strangeness $S=-1,-2$ sectors are explicitly taken into account. In two-body space, such transitions may lead coupling between states of identical particles and non-identical ones. Therefore, a careful consideration is required when determining combinatorial factors that connect many-body potential matrix elements free-space potentials. Using second quantization, we systematically derive question for $S=0,-1,-2$ sectors. As first application, use J-NCSM investigate $\Lambda \Lambda$ s-shell hypernuclei based on hyperon-hyperon (YY) potentials derived within chiral effective field theory at leading order (LO) up next-to-leading (NLO). find LO overbinds $^{\text{ }\text{ } \text{}6}_{\Lambda \Lambda}\text{He}$ while prediction NLO interaction close experiment. Both interactions also yield bound state \text{}5}_{\Lambda \Lambda}\text{He}$. The $^{\text{}\text{ }\text{}4}_{\Lambda \Lambda}\text{H}$ system predicted be unbound.