We study the dinucleon (dineutron and diproton) correlation of the ground states of ${}^9\mathrm{Li}$, ${}^{10}$Be, and ${}^{9,10}\mathrm{C}$. We assume an $\alpha +t$ core for ${}^9\mathrm{Li}$, an $\alpha +\alpha$ core for ${}^{10}$Be and ${}^{10}\mathrm{C}$, and an $\alpha {+}^3$He core for ${}^9\mathrm{C}$, and investigate the effect of core structure changes on the degree of dineutron formation and spatial expansion from the core. For ${}^9\mathrm{Li}$, $t$ 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 ${}^9\mathrm{Li}$, the dineutron of ${}^{10}$Be dissociates largely due to the stronger spin-orbit attraction from the $\alpha +\alpha$ core than the $\alpha +t$ core. We also investigate diproton features in ${}^{9,10}\mathrm{C}$, the mirror nuclei of ${}^9\mathrm{Li}$ and ${}^{10}$Be, respectively, and compare them with the dineutron features of ${}^9\mathrm{Li}$ 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.

• Received 29 November 2013
• Revised 8 February 2014

DOI:https://doi.org/10.1103/PhysRevC.89.024315