High spin band structures in doubly-odd $^{194}$Tl

TL;DR

This study extends the level scheme of the $^{194}$Tl nucleus to higher energies, identifies new band structures including a magnetic rotational band, and compares experimental data with theoretical models to understand shape and band crossing phenomena.

Contribution

The paper reports the first observation of two new 6-quasiparticle band structures in $^{194}$Tl, including a magnetic rotational band, and provides detailed experimental and theoretical analysis.

Findings

Extended the level scheme of $^{194}$Tl up to 4.1 MeV.

Observed two new 6-quasiparticle band structures.

Identified a magnetic rotational band in $^{194}$Tl.

Abstract

The high-spin states in odd-odd $^{194}$Tl nucleus have been studied by populating them using the $^{185,187}$Re($^{13}$C, xn) reactions at 75 MeV of beam energy. $\gamma-\gamma$ coincidence measurement has been performed using the INGA array with a digital data acquisition system to record the time stamped data. Definite spin-parity assignment of the levels was made from the DCO ratio and the IPDCO ratio measurements. The level scheme of $^{194}$Tl has been extended up to 4.1 MeV in excitation energy including 19 new gamma ray transitions. The $\pi h_{9/2} \otimes \nu i_{13/2}$ band, in the neighboring odd-odd Tl isotopes show very similar properties in both experimental observables and calculated shapes. Two new band structures, with 6-quasiparticle configuration, have been observed for the first time in $^{194}$Tl. One of these bands has the characteristics of a magnetic rotational band. The cranked shell model calculations, using a deformed Woods-Saxon potential, have been performed to obtain the total Routhian surfaces in order to study the shapes of the bands and the band crossing in $^{194}$Tl. The semiclassical formalism has been used to describe the magnetic rotational band.