Few-body structures in the mirror nuclei, ${}^{11}$O and ${}^{11}$Li

Abstract

We investigate the dripline mirror nuclei, ${}^{11}$Li and ${}^{11}$O, located on the neutron and proton dripline, respectively. We calculate the lowest four states, $3/2^{-}$, $1/2^{+}$, $3/2^{+}$ and $5/2^{+}$, built on double occupancy in the nuclear $s_{1/2}$ and $p_{1/2}$ valence single-particle states. We use the hyperspherical adiabatic expansion method to solve the three-body problem for a frozen nuclear core surrounded by two identical nucleons. The four analogue states in ${}^{11}$O are obtained with precisely the same interactions as used for the four states in ${}^{11}$Li, except for addition of the Coulomb interaction from the charge of the substituted valence protons. Surprisingly the four energies deviate from each other only by less than a few hundred keV. Any of them could then turn out to be the ground state, due to the uncertainty related to the angular momentum and parity dependence of the three-body potential. Still, our calculations marginally favor the $1/2^{+}$ state. The structures of these four states in ${}^{11}$O deviate substantially from the analogue states in the mirror, ${}^{11}$Li.

Comments: To be published in Physical Review C