Comment on "Spin-trap isomers in deformed, odd-odd nuclei in the light rare-earth region near $N=98$"

TL;DR

This paper challenges a recent claim of a new isomeric state in $^{162}$Tb, showing that the reported state is actually the ground state and the proposed isomer is likely a contaminant, based on existing data.

Contribution

The authors refute a recent experimental identification of a new isomeric state in $^{162}$Tb, clarifying the true ground state and contaminant status through data analysis.

Findings

The reported $(4^-)$ state is incompatible with existing data.

The identified isomeric state is actually the $1^-$ ground state.

The supposed ground state is likely a molecular contaminant.

Abstract

A new isomeric $(4^-)$ state at 285.5(32) keV in $^{162}$Tb was reported by R. Orford et al. [Phys. Rev. C 102, 011303(R) (2020)] based on a Penning-trap mass measurement. Here we show that this result is not compatible with existing experimental data. The state identified as $^{162}$Tb$^{m}$ with a mass-excess value of $-65593.9(25)$ keV is actually the $1^-$ ground state. The state identified as the ground state of $^{162}$Tb is most likely a molecular contaminant with the same mass-over-charge ratio.