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

Abstract:

The β-decay of ¹⁴⁶La was studied using the on-line isotope separator KUR-ISOL. Gamma-gamma 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 δ_183.2= 0.25 ± 0.08, δ_638.9= 0.33 ± 0.05, δ_959.0= 1.19^+0.16 _−0.14, δ_1015.9= 5.4^+3.1 _−1.5 and δ_1318.1= 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 ¹⁴⁶Ce is discussed based on the results of calculation using the IBM-2 theory.