Shape Evolution of C Isotopes in (β, γ) Deformation Plane

We study the shape evolution of C isotopes in the full (β, γ) deformation plane using a constrained Skyrme Hartree-Fock + BCS method in coordinate space. It is shown that the deformation of the energy minimum varies markedly in the (β, γ) plane as a function of mass number, which can be viewed as a clear manifestation of the spontaneous symmetry breaking effect in finite many-body systems. We also study the difference in deformations between protons and neutrons in the total (β, γ) plane. It is found that the proton and neutron quadrupole moments are almost the same in light C isotopes, while the neutron quadrupole moment is about 3 times larger than the proton one in C isotopes heavier than ¹⁶C. The isospin symmetry of the mirror nuclei ¹⁰C and ¹⁰Be is also examined in connection with the deformation in the (β, γ) plane.