TY  - JOUR
AU  - Chen, Z. Q. et al
AU  - Montaner-Piza, A.
PY  - 2019
DA  - 2019//
TI  - Proton Shell Evolution below Sn-132: First Measurement of Low-Lying beta-Emitting Isomers in Ag-123,Ag-325
T2  - Phys. Rev. Lett.
JO  - Physical Review Letters
SP  - 212502
EP  - 6pp
VL  - 122
IS  - 21
PB  - Amer Physical Soc
AB  - The beta-delayed gamma-ray spectroscopy of neutron-rich Ag-123,Ag-325 isotopes is investigated at the Radioactive Isotope Beam Factory of RIKEN, and the long-predicted 1/2(-) beta-emitting isomers in Ag-123,Ag-325 are identified for the first time. With the new experimental results, the systematic trend of energy spacing between the lowest 9/2(+) and 1/2(-) levels is extended in Ag isotopes up to N = 78, providing a clear signal for the reduction of the Z = 40 subshell gap in Ag towards N = 82. Shell-model calculations with the state-of-the-art V-MU plus M3Y spin-orbit interaction give a satisfactory description of the low-lying states in Ag-123,Ag-325. The tensor force is found to play a crucial role in the evolution of the size of the Z = 40 subshell gap. The observed inversion of the single-particle levels around Ag-123 can be well interpreted in terms of the monopole shift of the pi 1g(9/2) orbitals mainly caused by the increasing occupation of nu 1h(11/2) orbitals.
SN  - 0031-9007
UR  - https://doi.org/10.1103/PhysRevLett.122.212502
DO  - 10.1103/PhysRevLett.122.212502
LA  - English
N1  - WOS:000469334100003
ID  - Chen+Montaner-Piza2019
ER  -