Precise Mass Measurement of the Longest Odd-Odd Chain of \boldmath $1^{+}$ Ground States

Abstract

Precise mass measurements of the ground and isomeric states of the odd-odd ${}^{108,110,112,114,116}$Rh were performed using the Canadian Penning Trap at Argonne National Laboratory, showing good agreement with recent JYFLTRAP measurements. A new possible isomeric state of ${}^{114}$Rh was also observed. These isotopes are part of the longest odd-odd chain of identical ground-state spin-parity assignment of 1${}^{+}$, spanning ${}^{104-118}$Rh, despite being in a region of deformation. Realistic phenomenological mean-field calculations using ``universal'' Wood-Saxon Hamiltonian were performed, which explained this phenomenon for the first time. In addition, multi-quasiparticle blocking calculations were performed to study the configuration of low-lying states in the odd-odd Rh nuclei, elucidating anomalous isomeric yield ratio observed for ${}^{114}$Rh.