New high-spin structure and possible chirality in $^{109}$In

TL;DR

This study investigates the high-spin structure of $^{109}$In, revealing new energy levels, bands, and potential chirality, supported by experimental data and theoretical calculations indicating shape evolution.

Contribution

The paper extends the level scheme of $^{109}$In with 46 new gamma rays and proposes possible nuclear chirality based on combined experimental and theoretical analysis.

Findings

46 new gamma-ray transitions identified

Observation of eight bands, including six dipole bands

Possible nuclear chirality suggested in $^{109}$In

Abstract

High-spin structure of $^{109}$In has been investigated with the $^{100}$Mo($^{14}$N, 5$n$)$^{109}$In reaction at a beam energy of 78 MeV using the in-beam $\gamma$ spectroscopic method. The level scheme of $^{109}$In has been modified considerably and extended by 46 new $\gamma$-rays to the highest excited state at 8.979 MeV and $J^{\pi}$=(45/2$^{+}$). The new level scheme consists of eight bands, six of which are identified as dipole bands. The configurations have been tentatively assigned with the help of the systematics of neighboring odd-$A$ indium isotopes and the experimental aligned angular momenta. The dipole bands are then compared with the titled axis cranking calculation in the framework of covariant density function theory (TAC-CDFT). The results of theoretical calculation based on the configurations, which involve one proton hole at the $g_{9/2}$ orbital and two or four unpaired neutrons at $g_{7/2}$, $d_{5/2}$ and $h_{11/2}$ orbitals, show that the shape of $^{109}$In undergoes an evolution on both $\beta$ and $\gamma$ deformations and possible chirality is suggested in $^{109}$In.