K. Kato

Systematic description of the Li6(n,n′)6Li *→d+α reactions with the microscopic coupled-channels method

We investigate {sup 6}Li(n,n{sup }){sup 6}Li{sup *}{yields}d+{alpha} reactions by using the continuum-discretized coupled-channels method with the complex Jeukenne-Lejeune-Mahaux effective nucleon-nucleon interaction. In this study, the {sup 6}Li nucleus is described by a d+{alpha} cluster model. The calculated elastic cross sections for incident energies between 7.47 and 24.0 MeV are in good agreement with experimental data. Furthermore, we show that the neutron spectra for {sup 6}Li breakup states measured at selected angular points and incident energies can be also reproduced systematically.

Development of Experimental Nuclear Reaction Data File for Astrophysics

Experimental nuclear reaction data compilation activity in Japan for the NRDF database and international collaboration of experimental nuclear reaction data exchange by the EXFOR format are presented. Recent development of an experimental nuclear reaction data file (NRDF/A) for astrophysics, which is based on the EXFOR compilation, is also introduced. All services are available at http://www.jcprg.org/.

Gamow states and continua in the cluster-orbital shell model approach

Importance of the unbound states in loosely bound systems by comparing to the stable nuclei is investigated. We use the cluster-orbital shell model (COSM) approach and expand the wave function using the complete set of the single-particle states. The completeness relation is constructed by the Berggren metrics, which includes bound, resonant and anti-bound states, and continua. We precisely investigated such the contributions of the resonant states (Gamow states) and continua in the helium isotopes and compare them those obtained by the Gamow shell model.

Di-trinucleon resonance states of A=6 systems in a microscopic cluster model

Highly excited resonance states lying above the t+t threshold in {sup 6}He are theoretically studied by the t+t microscopic two-cluster model. The t+t two-body scattering problem is solved by the microscopic R-matrix method in order to localize resonance states. Excited states of {sup 6}Be and {sup 6}Li (both T=1 and 0) are as well studied within the consistent two-cluster models. We have employed four different effective nucleon-nucleon interactions in order to check the sensitivity to our results and we have obtained fairly consistent results in every interaction. In positive parity states, our model gives deeply bound states which are well-known low-lying {alpha}+n+n three-body states and these states are obtained through the overlap between the t+t and {alpha}+n+n configurations at smaller cluster relative distance. Similar bound states are found in the T=0 state in {sup 6}Li. In negative parity states, our calculation shows broad 0{sup -} and 2{sup -} P-wave resonances just above the t+t threshold and in addition three F-wave resonances of 2{sup -}, 3{sup -}, and 4{sup -} at higher energies with broader widths. Our calculations show that the noncentral term of the effective nucleon-nucleon interaction plays an important role for these broad resonance states. T=0 states of {supmorexa0» 6}Li show single broad resonances in P- and F-waves, respectively, and their positions are very close to those of T=1 resonances.«xa0less