In-band M1 and E2 transition rates and collective structures in 128Ba

Subpicosecond mean lifetimes of eight excited states in 128Ba populated via the 96Zr(36S,4n) reaction were measured by the Doppler-shift attenuation (DSA) technique using a line-shape analysis. The differential decay-curve method (DDCM) was applied for the lifetime determination. The B(E2) values in the yrast band indicate that the first band-crossing is with a proton S-band. The configuration View the MathML source of the negative-parity semi-decoupled bands is confirmed by the measured B(E2, I → I − 2) and B(M1, I → I − 1) transition strengths. The higher-lying “dipole” band in 128Ba can be described as a high-K four-quasiparticle band built on the prolate configuration View the MathML source.