Band structures and intruder $\pi$$i_{13/2}$ state in $^{197}$Tl

TL;DR

This study investigates the excited states and band structures of the $^{197}$Tl nucleus, identifying a new band and evidence for an intruder $_{13/2}$ state, using gamma spectroscopy and theoretical shape calculations.

Contribution

First identification of a new band structure and evidence for an intruder $_{13/2}$ state in $^{197}$Tl through experimental and theoretical analysis.

Findings

Discovery of a new band structure in $^{197}$Tl

Evidence for the intruder $_{13/2}$ state

Shape analysis via Routhian surface calculations

Abstract

The excited states in the odd-$A$ $^{197}$Tl nucleus have been studied by populating them using the $^{197}$Au($\alpha$, 4$n$)$^{197}$Tl reaction at the beam energy of 48 MeV. The $\gamma-\gamma$ coincidence data were taken using a combination of clover, LEPS and single crystal HPGe detectors. Precise spin and parity assignments of the excited states have been done through the polarization and the DCO measurements. A new band structure has been identified and the evidence for a possible intruder $\pi i_{13/2}$ state has been found for the first time. Possible configurations of the observed bands have been discussed. The total Routhian surface calculations have been performed to study the shape of $^{197}$Tl for different configurations.