Přispěvatelé: |
C., Plettner, H., Grawe, I., Mukha, J., Döring, F., Nowacki, L., Batist, A., Blazhev, C. R., Hoffman, Z., Jana, R., Kirchner, LA COMMARA, Marco, C., Mazzocchi, E., Roeckl, R., Schwengner, S. L., Tabor, M., Wiedeking |
Popis: |
The β decay of 94 Ag, a nucleus with three proton and three neutron holes with respect to 100 Sn, was investigated at the GSI on-line mass separator by using an array of germanium and silicon detectors. On the basis of a βγγ coincidence measurement, the previously reported decay scheme has been considerably improved and evidence is presented for a spin–gap isomer with a spin-parity assignment of (21 + ), i.e., the highest spin ever observed in β decay. The half-life of the low-spin isomer (7 + ) was remeasured to be 0.59(2) s, whereas the half-life of the high-spin isomer was determined as 0.47(8) s. For the states in 94 Ag and 94 Pd, large-scale shell-model calculations that include up to 4p–4h excitations across the N = Z =50 shell gap and employ a realistic interaction were carried out. These core excitations play a crucial role in generating the E 4 isomerism required for the interpretation of the long half-life of the (21 + ) state in 94 Ag. |