title: Five-body cluster structure of the double-Λ hypernucleus (ΛΛ)(11)Be.
abstract: Energy levels of the double Λ hypernucleus (ΛΛ)(11)Be are calculated within the framework of a ααnΛΛ five-body model. Interactions between constituent particles are determined so as to reproduce reasonably the observed low-energy properties of the αα, ααn nuclei and the existing data for Λ-binding energies of the αΛ, ααΛ, αnΛ, and ααnΛ systems. An effective ΛΛ interaction is constructed so as to reproduce, within the αΛΛ three-body model, the B(ΛΛ) of (ΛΛ)(6)He, which was extracted from the emulsion experiment, the NAGARA event. With no adjustable parameters for the ααnΛΛ system, B(ΛΛ) of the ground and bound excited states of (ΛΛ)(11)Be are calculated with the Gaussian expansion method. The Hida event, recently observed at KEK-E373 experiment, is interpreted as an observation of the ground state of the (ΛΛ)(11)Be.
authors.affiliation: RIKEN Nishina Center, RIKEN, Hirosawa 2-1,Wako,Saitama, 351-0198, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Hiyama
authors.forename: M
authors.initials: M
authors.lastname: Kamimura
authors.forename: Y
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: T
authors.initials: T
authors.lastname: Motoba