Proton dominance in the 2^+_2 -> 0^+_1 transition of N = Z\pm 2 nuclei around Si-28

Abstract

E2 transitions in Si-30 are investigated in relation with intrinsic deformations based on a method of antisymmetrized molecular dynamics. By comparing E2 transition strengths in the mirror nuclei Si-30 and S-30, transition matrix amplitudes M_p and M_n for protons and neutrons are discussed in mirror analysis. Particular attention is paid to the M_n/M_p ratio in the transition from the 2^+_2 state to the 0^+_1 state. The M_n/M_p ratio in Mg-26 and Si-26 is also investigated. It is found that the proton dominance in the transition 2^+_2 -> 0^+_1 in Si-30 and Si-26 originates in the oblate trend of the Z=14 proton structure.

Comments: 7 pages, 7 figures