Structure of the Excited States in 12C. II

Abstract

Nuclear wave functions of microscopic a-particle model, which were obtained in the generator coordinate calculation by the present authors, are found to reproduce properties of low energy levels of 12 C nucleus, i.e., a-decay widths, electric transitions and charge form factors for electron scattering. Especially calculated widths of the Oz +and 10.3 MeV levels are found to be in excellent agreement with experiment, assuming that the spin of the latter is 2. The monopole transition from the o, + state to the ground state is also well reproduced as well as the E2 transition to the 2, + state. Furthermore analysis of the reduced width amplitudes is made which clarifies characters of the levels. It is found that in the o, + and 10.3 MeV states an a-particle is coupled mainly to the 'Be ground state with orbital angular momenta l equal to 0 and 2 respectively. In the predicted higher positive-parity states O, +, 2, + and 4, +, an a-particle is coupled mainly to the first excited state of 'Be with l equal to 2. 1. Introduction