Investigation of the 3/22−state of9Li with microscopic structure and reaction models

Abstract

The low-lying states of the ${}^{9}$Li nucleus are investigated with a unified framework of microscopic structure and reaction models. In the structure model, the wave function is fully antisymmetrized and the ${}^{9}$Li nucleus is described as an $\ensuremath{\alpha}$+$t$+$n$+$n$ four-body system, and low-lying 1/2${}^{\ensuremath{-}}$, 3/2${}^{\ensuremath{-}}$, 5/2${}^{\ensuremath{-}}$, and 7/2${}^{\ensuremath{-}}$ states are obtained by the stochastic multiconfiguration mixing method. Using these wave functions, the quasielastic cross section at $E/A$ = 60 MeV and the elastic and inelastic cross sections at $E/A$ = 50 MeV on the ${}^{12}$C target are calculated in the framework of the microscopic coupled channel (MCC) method. The characteristic inelastic angular distribution is seen in the 3/2${}_{2}^{\ensuremath{-}}$ state, whose $\ensuremath{\alpha}$+$t$ cluster structure and valence neutron configurations are discussed in detail. We find the possibility of triaxial deformation and mixing of dineutron components in the ${}^{9}$Li nucleus.