6533b7d1fe1ef96bd125c0f6

RESEARCH PRODUCT

βdecay of the5+isomer of the odd-odd nucleus100Nb

subject

description

The decay of the $3s$ isomer of ${}^{100}\mathrm{Nb}$ has been investigated by $\ensuremath{\gamma}$ spectroscopy of online mass separated ${}^{100}\mathrm{Nb}.$ Several new transitions in the daughter nucleus ${}^{100}\mathrm{Mo}$ have been observed. This results in a more consistent decay pattern leading to a firm ${5}^{+}$ assignment to the ${}^{100}\mathrm{Nb}$ isomer. A QRPA based calculation reproduces the decay features best if the $\ensuremath{\pi}{g}_{9/2}\ensuremath{-}\ensuremath{\pi}{p}_{1/2}$ gap is enlarged, confirming the importance of the subshell gap at $Z=40$ previously introduced to account for low-lying ${0}^{+}$ states in other $N=58$ isotones.