Dinucleon correlations in the ground states of9Li,10Be, and9,10C

Abstract

We study the dinucleon (dineutron and diproton) correlation of the ground states of ${}^{9}Li$, ${}^{10}$Be, and ${}^{9,10}C$. We assume an $\ensuremath{\alpha}+t$ core for ${}^{9}Li$, an $\ensuremath{\alpha}+\ensuremath{\alpha}$ core for ${}^{10}$Be and ${}^{10}C$, and an $\ensuremath{\alpha}{+}^{3}$He core for ${}^{9}C$, and investigate the effect of core structure changes on the degree of dineutron formation and spatial expansion from the core. For ${}^{9}Li$, $t$ cluster breaking in the core significantly enhances the dineutron component inside the nuclei. Moreover, its component markedly depends on the strength of the spin-orbit interaction since a dineutron is fragile and dissociates readily due to the spin-orbit interaction. Compared with ${}^{9}Li$, the dineutron of ${}^{10}$Be dissociates largely due to the stronger spin-orbit attraction from the $\ensuremath{\alpha}+\ensuremath{\alpha}$ core than the $\ensuremath{\alpha}+t$ core. We also investigate diproton features in ${}^{9,10}C$, the mirror nuclei of ${}^{9}Li$ and ${}^{10}$Be, respectively, and compare them with the dineutron features of ${}^{9}Li$ and ${}^{10}$Be. No qualitative difference is observed between diprotons and dineutrons in the degree of formation at the surface, but a quantitative difference may exist in the degree of dinucleon-size change far from the core.