Structure of the Excited States in 12C. II

Abstract

Nuclear wave functions of microscopic α-particle, model, which were obtained in the generator coordinate calculation by the present authors, are found to reproduce properties of low energy levels of 12C nucleus, i. e., α-decay widths, electric transitions and charge form factors for electron scattering. Especially calculated widths of the 02+ and 10.3MeV levels are found to be in excellent agreement with experiment, assuming that the spin of the latter is 2. The monopole transition from the 02+ state to the ground state is also well reproduced as well as the E2 transition to the 21+ state. Furthermore analysis of the reduced width amplitudes is made which clarifies characters of the levels. It is found that in the 02+ and 10.3MeV states an α-particle is coupled mainly to the 8Be ground state with orbital angular momenta l equal to 0 and 2 respectively. In the predicted higher positive-parity states 03+, 23+ and 42+, an α-particle is coupled mainly to the first excited state of 8Be with l equal to 2.