S. Fujii

Ground-state and single-particle energies of nuclei around 16O, 40Ca, and 56Ni from realistic nucleon-nucleon forces.

We perform ab initio calculations for nuclei around 16O, 40Ca, and 56Ni using realistic nucleon-nucleon forces. In particular, 56Ni is computed as the heaviest nucleus in this kind of ab initio calculation. Ground-state and single-particle energies including three-body-cluster effects are obtained within the framework of the unitary-model-operator approach. It is shown that the CD-Bonn nucleon-nucleon potential gives quite good results close to the experimental values for all nuclei in the present work.

Three-Body Cluster Effects on Λ Single-Particle Energies in Λ17O and Λ41Ca

A method for a microscopic description of Lambda hypernuclei is formulated in the framework of the unitary-model-operator approach. A unitarily transformed hamiltonian is introduced and given in a cluster expansion form. The structure of three-body-cluster terms are discussed especially on the Lambda single-particle energy. The Lambda single-particle energies including the three-body-cluster contributions are calculated for the 0s_{1/2}, 0p_{3/2} and 0p_{1/2} states in_{Lambda}^{17}O, and for the 0s_{1/2}, 0p_{3/2}, 0p_{1/2}, 0d_{5/2}, 0d_{3/2} and 1s_{1/2} states in_{Lambda}^{41}Ca, using the Nijmegen soft-core (NSC), NSC97a-f, the Juelich A (J A) and J B hyperon-nucleon interactions. It is indicated that the three-body-cluster terms bring about sizable effects in the magnitudes of the Lambda single-particle energies, but hardly affect the Lambda spin-orbit splittings.A method to obtain microscopic descriptions of Λ hypernuclei is formulated in the framework of the unitary-model-operator approach. A unitarily transformed Hamiltonian is introduced and given in a cluster expansion form. The structure of three-body cluster terms are discussed, in particular, with regard to the Λ single-particle energy. The Λ single-particle energies including the three-body cluster contributions are calculated for the 0s1/2 ,0 p3/2 and 0p1/2 states in 17 O, and for the 0s1/2 ,0 p3/2 ,0 p1/2 ,0 d5/2 ,0 d3/2 and 1s1/2 states in 41 Ca, us

Unitary-model-operator approach to Λ hypernuclei

Abstract The unitary-model-operator approach (UMOA) is formulated for the description of lambda hypernuclei. The method is applied to Λ17O. A lambda-nucleon effective interaction is derived, taking the coupling of the sigma-nucleon channel into account. The lambda single-particle energies are calculated for the 0s 1 2 , 0p 3 2 and 0p 1 2 states employing the Nijmegen soft-core (NSC), Julich model-A (JA) and model-B (JB) hyperon-nucleon potentials.

Shell-model calculations of Λ17O using microscopic ΛN and ΣN effective interactions

Shell-model calculations in a large model space are performed for the low-lying 1/2+, 3/2− and 1/2− states in Λ17O, introducing effective interactions among the Λ, Σ and nucleons. The effective interactions are derived from hyperon-nucleon and nucleon-nucleon interactions given in free space in the framework of the unitary-model-operator approach. The results are compared with those obtained in a perturbative method studied previously, and reliability of the present method is discussed.

Three-Body-Cluster Effects on Lambda Single-Particle Energies in _{Lambda}^{17}O and_{Lambda}^{41}Ca

A method for a microscopic description of Lambda hypernuclei is formulated in the framework of the unitary-model-operator approach. A unitarily transformed hamiltonian is introduced and given in a cluster expansion form. The structure of three-body-cluster terms are discussed especially on the Lambda single-particle energy. The Lambda single-particle energies including the three-body-cluster contributions are calculated for the 0s_{1/2}, 0p_{3/2} and 0p_{1/2} states in_{Lambda}^{17}O, and for the 0s_{1/2}, 0p_{3/2}, 0p_{1/2}, 0d_{5/2}, 0d_{3/2} and 1s_{1/2} states in_{Lambda}^{41}Ca, using the Nijmegen soft-core (NSC), NSC97a-f, the Juelich A (J A) and J B hyperon-nucleon interactions. It is indicated that the three-body-cluster terms bring about sizable effects in the magnitudes of the Lambda single-particle energies, but hardly affect the Lambda spin-orbit splittings.A method to obtain microscopic descriptions of Λ hypernuclei is formulated in the framework of the unitary-model-operator approach. A unitarily transformed Hamiltonian is introduced and given in a cluster expansion form. The structure of three-body cluster terms are discussed, in particular, with regard to the Λ single-particle energy. The Λ single-particle energies including the three-body cluster contributions are calculated for the 0s1/2 ,0 p3/2 and 0p1/2 states in 17 O, and for the 0s1/2 ,0 p3/2 ,0 p1/2 ,0 d5/2 ,0 d3/2 and 1s1/2 states in 41 Ca, us