Systematic Study of 9,10,11Li with the Tensor and Pairing Correlations

Abstract

We make a systematic study of Li isotopes (A = 9, 10, 11) in the tensor optimized shell model for 9 Li and treat the additional valence neutrons in the cluster model approach by taking into account the Pauli-blocking effect caused by the tensor and pairing correlations. We describe the tensor correlations in 9 Li fully in the tensor-optimized shell model, where the variation of the size parameters of the single particle orbits is essential for getting strong tensor correlations. We have shown in our previous study that in 10,11 Li the tensor and pairing correlations in 9 Li are Pauli-blocked by additional valence neutrons, which make the p-shell configurations pushed up in energy. As a result, the s 2 valence neutron component increases to reveal the halo structure of 11 Li and the inversion phenomenon of the single particle spectrum in 10 Li arises. Following the previous study, we demonstrate the reliability of our framework by performing a detailed systematic analysis of the structures of 9,10,11 Li, such as the charge radius, the spatial correlation of halo neutrons of 11 Li and the electromagnetic properties of Li isotopes. The detailed effects of the Pauli-blocking on the spectroscopic properties of 10,11 Li are also discussed. It is found that the blocking acts strongly for the 11 Li ground state rather than for 10 Li and for the dipole excited states of 11 Li, which is mainly caused by the interplay between the tensor correlation in 9 Li and the halo neutrons. The results obtained in these analyses clearly show that the inert core assumption of 9 Li is not realistic to explain the anomalous structures observed in 10,11 Li. For the dipole excitation spectrum of 11 Li, the effect of the final state interactions is discussed in terms of the dipole strength function. * )

Virtual-state character of theBe91/2+state in theBeOdsuren1, Kikuchi2, Myo3 et al. 2015Phys. Rev. C387921View full textAdd to dashboardCite

“…The existence of the virtual state is consistent with the dominant decay into 8 Be + n in the photodisintegration of 9 Be. The virtual state is often discussed in unstable nuclei, such as 10 Li and 11 Li [25,26,38]. For 10 Li, Masui et al [38] showed the explicit pole trajectory of the virtual state of 10 Li as a 9 Li + n picture, which is similar to the present 8 Be(0 + ) + n situation.…”

“…Furthermore, the CSM has been developed to describe the breaking up of unstable nuclei. The CSM has been applied to the Coulomb breakup reactions of two-neutron halo nuclei into core + n + n scattering states and well reproduces the observed cross sections [24][25][26]. From the above, the CSM is promising means to discuss the excited states of 9 Be and the photodisintegration into unbound excited states of 9 Be on the same footing.…”

Tensor-optimized shell model for the Li isotopes with a bare nucleon-nucleon interaction

“…In our previous study of 11 Li, we discuss those quantities of 11 Li in detail [25,26]. It is interesting to discuss the effect of the tensor force on these quantities in other Li isotopes using the TOSM+UCOM method.…”

“…Before the present analysis, for neutron-rich 10 Li and 11 Li, we have performed the coupled two-and three-body cluster model analyses assuming the 9 Li core described using the simplified TOSM wave function, respectively [6,25,26]. The cluster model for two nuclei precisely describes the neutron wave functions in a loosely bound state around 9 Li, such as a neutron halo structure in 11 Li.…”

Spatial Structure of Cooper Pairs in Nuclei

“…[22][23][24][25][26][27][28][29][30] A common prediction is that the valence halo neutrons exhibit a spatial correlation favoring the 'di-neutron' configuration with two neutrons coupled at small relative distances. The spatial correlation is also discussed in stable heavy nuclei with closed-shell core plus two neutrons, e.g.…”