Band structure of 146Ce studied through γ-γ angular correlation measurements

Abstract

The β-decay of 146 La was studied using the on-line isotope separator KUR-ISOL. Gammagamma angular correlation measurements were performed with a 4-Ge detectors system. Spin assignments of three levels were made: 3 + for the 1576.5 keV level, 4 + for the 1627.1 keV level and 5 + for the 1810.2 keV level. The mixing ratios (E2/M1) were deduced to be δ183.2 = 0.25±0.08, δ638.9 = 0.33±0.05, δ959.0 = 1.19 +0.16 −0.14 , δ1015.9 = 5.4 +3.1 −1.5 and δ1318.1 = 6.5 +1.7 −1.1 . These were compared to the calculated values obtained in three cases involving different Majorana force parameter values. The band structure of 146 Ce is discussed based on the results of calculation using the IBM-2 theory.