Possible Shape Coexistence and Magnetic Dipole Transitions in 17C and 21Ne
Abstract
Magnetic dipole(M1) transitions of N=11 nuclei, 17C and 21Ne are investigated by using shell model and deformed Skyrme Hartree-Fock+blocked BCS wave functions. Shell model calculations predict well observed energy spectra and magnetic dipole transitions in 21Ne, while the results are rather poor to predict these observables in 17C. In the deformed HF calculations, the ground states of two nuclei are shown to have large prolate deformations close to β2=0.4. It is also pointed out that the first Kπ=1/2+ state in 21Ne is prolately deformed, while the first Kπ=1/2+ state in 17C is predicted to have a large oblate deformation being close to the ground state in energy, We point out that experimentally observed large hindrance of M1 transition between Iπ=1/2+ and 3/2+ in 17C can be attributed to a shape coexistence near the ground state of 17C.