Gamow Shell Model Description of Neutron-Rich Nuclei

Abstract

This work presents the first continuum shell-model study of weakly bound neutron-rich nuclei involving multiconfiguration mixing. For the single-particle basis, the complex-energy Berggren ensemble representing the bound single-particle states, narrow resonances, and the non-resonant continuum background is taken. Our shell-model Hamiltonian consists of a one-body finite potential and a zero-range residual two-body interaction. The systems with two valence neutrons are considered. The Gamow shell model, which is a straightforward extension of the traditional shell model, is shown to be an excellent tool for the microscopic description of weakly bound systems. It is demonstrated that the residual interaction coupling to the particle continuum is important; in some cases, it can give rise to the binding of a nucleus.

Density matrix renormalization group approach to two-fluid open many-fermion systems

“…This set of parameters has not been optimized to reproduce the actual structure of 7 Li and 8 Li. Our choice of interaction is motivated by the fact that the main purpose of this study is to test the DMRG procedure for proton-neutron systems for which the exact GSM diagonalization is still possible.…”

“…Our choice of interaction is motivated by the fact that the main purpose of this study is to test the DMRG procedure for proton-neutron systems for which the exact GSM diagonalization is still possible. In this context, our 7 Li and 8 Li systems should be viewed as threeand four-nucleon cases, respectively.…”

“…The s.p. basis of 7 Li is generated by the HF potential (calculated separately for protons and neutrons and for each partial wave). It contains bound s.p.…”

“…The solution of the configuration-interaction problem in the presence of continuum states has been recently advanced in the real-energy continuum SM [4][5][6] and in the complex-energy SM, the so-called Gamow shell model (GSM) [7][8][9][10][11]. In the GSM, the s.p.…”

“…IV. Illustrative calculations are carried out for 7 Li (three-nucleon systems) and 8 Li (four-nucleon systems). We study the impact of different starting conditions on the DMRG result and introduce two different truncation schemes in the DMRG procedure and discuss their virtues.…”