Decay properties of the 3(1)(-) level in Mo-96

The first excited 3(1)(-) level of Mo-96 was investigated in a high-statistics experiment using the Mo-95(n, gamma gamma) cold neutron capture reaction. The measurements used the high cold neutron flux from the research reactor at Institut Laue-Langevin and employed the highly-efficient EXILL array to detect gamma-ray coincidences. The recorded statistics allow identification of decay branches with only a small relative intensity including the 3(1)(-) ( )-> 0(gs)(+) E3 decay. With the knowledge of the newly measured branching ratio and the known B (E3 , 3(1)(-) -> 0(gs)(+)) transition probability, the lifetime of the 3(1)(-) level was determined and, subsequently, the B (E1) strength of the other decay branches of the 3(1)(-) octupole phonon were calculated. The extracted electromagnetic decay strengths are compared to the systematics of the stable even-even molybdenum isotopes and values calculated in a Skyrme-force based quasi-particle random phase approximation and in a cluster approach. Additionally, the 3(1)(-) -> 2(iv)(+) decay branch to the low-lying 2(iv)(+) quadrupole isovector level was observed.