S = -2 Hypernuclear Structure

The structure of light hypernuclei with strangeness S = -2 is investigated with the three-, four-, and five-body cluster model and the Gaussian Expansion method (GEM). Energy levels of the double-Lambda hypernuclei (7_{Lambda) Lambda}He, (7_{Lambda) Lambda}Li, (8_{Lambda) Lambda}Li, (9_{Lambda) Lambda}Li, (9_{Lambda) Lambda}Be, and (10) _{Lambda Lambda}Be are predicted with the framework of alpha Lambda Lambda four-body model, where x = n, p, d, t, (3) He, and alpha, respectively. Also, energy levels of the double Lambda hypernucleus, (11) _{Lambda Lambda}Be are calculated within the framework of a alpha alpha nLambda Lambda five-body model. The Demachi-Yanagi event, identified as (10) _{Lambda Lambda}Be, is interpreted as an observation of its 2(+) state excited state. The Hida event, recently observed at KEK-E373 experiment, is interpreted as an observation of the ground state of the (11) _{Lambda Lambda}Be. Detail

ed structure calculations in (12}_{Xi(-)) Be, (5}_{Xi(-)) H, (9}_{Xi(-)) Li, (7}_{Xi(-)) H and (\:10}_{Xi(-)) Li are performed within the framework of the microscopic two-, three- and four-body cluster models. (7}_{Xi(-)) H and (10}_{Xi(-)) Li are predicted to have bound states.