Shell-model study of light neutron-rich nuclei

Abstract

A large-scale shell-model calculation is applied to the study of radii of neutron-rich p-shell nuclei, using harmonic-oscillator and Hartree-Fock single-particle wave functions. The mass-number dependence of the radii of the Li and Be isotopes is well reproduced by the shell model calculations with HF wave functions except for 11 Li. Although the cofinfiguration mixing of sd shell to the ground state of 11 Li is about 10%, the radius is increased only by 1% from the value √〈 r 2 〉 m = 2.417 fm obtained by 0 khω shell-model calculations and is much smaller than the experimental value 3.10 ± 0.17 fm. We take into account also the effect of loosely bound single-particle states in the shell-model calculations together with the 2 khω configuration mixings in 11 Li and 11 Be. We then find that the radius of 11 Li is increased to be 2.84 fm and becomes close to the empirical value, while that of 11 Be is hardly affected by the loosely-bound Op 1 2 orbit.