Charge Density of ^23,24O with Isoscalar--Isovector Coupling Terms

The nonlinear isoscalar--isovector terms which are used to simulate the density dependence of the symmetry energy are considered in the relativistic mean field model. The charge density distributions of ^23,24O are investigated by considering the contribution from the isoscalar--isovector couplings. Contrarily to the uncertainty of the neutron radius of ²⁰⁸Pb, a considerable uncertainty exists for the charge radii of ^23,24O. The data-to-data correlation between the neutron thickness of ²⁰⁸Pb and that of ^23,24O is enhanced by the inclusion of the ρNN tensor coupling. This enhancement is closely related to the structural factor, the 2s_1/2 occupation of the out-layer neutrons.