The T = 1, isospin triplet states in A = 30 nuclei

The level structure of 30S was studied using the 28Si(tau, nanti p) reaction at Esub(tau) = 9.5 MeV, and Jsup(π) values were determined for some proton-emitting states by the neutron-proton angular correlation measurements. The Coulomb displacement energy of the isospin triplet state of A = 30 nuclei was analyzed using first-order perturbation theory. Large deviations from perturbation theory were found for the ground state, the 21+ state, the 31- state and the second excited 0+ state. These results might be explained by the effect of the pairing correlation of the two valence protons in 30S under the assumption of charge symmetry for the nucleon-nucleon interaction. (orig.)