On the multipole mixing ratio of the $1066$ keV transition from the 0.52 $\hat{I}¼s$ isomer of ${}^{180}$Hf

Abstract

The nucleus ${}^{180}$Hf is one of the most primary of examples of an axially symmetric prolate rotor. Combined with the presence of high-$K$ isomers, spectroscopic studies can provide important information on the nature of its single-particle levels. Precise measurements are essential for constraining nuclear models and interpreting the nature of such isomeric states. In this work, the nucleus ${}^{180}$Hf was populated using the proton pick-up reaction ${}^{181}$Ta(${}^{11}$B,${}^{12}$C)${}^{180}$Hf at beam energy of 47 MeV at Horia Hulubei National Institute of Nuclear Physics and Engineering (IFIN-HH). The spin of the 1374 keV state and the mixing ratio of the $1066$ keV transition have been measured, the latter with an increased precision compared to the previous value from literature. The presently measured spin of the 1374 keV state, currently assigned a tentative value of $(4_1^{-})$, favors one of the two different values reported in the literature. The particular state constitutes the band-head of a rotational band in ${}^{180}$Hf. The measured multipolarity mixing ratio of the inter-band transition $1374\to 309$ keV can provide important information for the testing and constraining of theoretical nuclear models used for the study of the intrinsic properties of ${}^{180}$Hf as well as its neighboring isotopes.