Study of excited states and observation of collective level structures in the odd–odd nucleus Bi

A. Herzáň; S. Juutinen; K. Auranen; T. Grahn; P. T. Greenlees; K. Hauschild; U. Jakobsson; R. Julin; S. Ketelhut; M. Leino; A. Lopez-Martens; T. Lönnroth; P. Nieminen; M. Nyman; J. Partanen; P. Peura; P. Rahkila; P. Ruotsalainen; M. Sandzelius; J. Sarén; C. Scholey; J. M. K. Slotte; J. Sorri; S. Stolze; J. Uusitalo

doi:10.1140/epja/s10050-020-00167-z

2024 Impact factor 2.8

Hadrons and Nuclei

Eur. Phys. J. A (2020) 56: 165
https://doi.org/10.1140/epja/s10050-020-00167-z

Regular Article – Experimental Physics

Study of excited states and observation of collective level structures in the odd–odd nucleus ${}^{194}$ Bi

A. Herzáň¹^,2^,3^*, S. Juutinen³, K. Auranen³, T. Grahn³, P. T. Greenlees³, K. Hauschild³^,5, U. Jakobsson³^,6, R. Julin³, S. Ketelhut³, M. Leino³, A. Lopez-Martens³^,5, T. Lönnroth⁴, P. Nieminen³^,7, M. Nyman³^,8, J. Partanen³, P. Peura³^,9, P. Rahkila³, P. Ruotsalainen³, M. Sandzelius³, J. Sarén³, C. Scholey³^,10, J. M. K. Slotte⁴, J. Sorri³^,11, S. Stolze³^,12 and J. Uusitalo³

¹ Institute of Physics, Slovak Academy of Sciences, SK, 84511, Bratislava, Slovakia
² Oliver Lodge Laboratory, University of Liverpool, Liverpool, L69 7ZE, UK
³ University of Jyvaskyla, Department of Physics, P.O. Box 35, FI-40014, University of Jyvaskyla, Finland
⁴ Physics, Faculty of Science and Engineering, Åbo Akademi University, 20500, Turku, Finland
⁵ Present address: CSNSM, IN2P3-CNRS, 91405, Orsay Campus, France
⁶ Present address: Laboratory of Radiochemistry, Department of Chemistry, University of Helsinki, P.O. Box 55, 00014, Helsinki, Finland
⁷ Present address: Fortum Oyj, Power Division, P.O. Box 100, 00048, Fortum, Finland
⁸ Present address: European Commission, Joint Research Centre, Retieseweg 111, 2440, Geel, Belgium
⁹ Present address: Helsinki Institute of Physics, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland
¹⁰ Present address: MTC Limited, Ansty Park, Coventry, CV7 9JU, UK
¹¹ Present address: Radiation and Nuclear Safety Authority-STUK, Laippatie 4, 00880, Helsinki, Finland
¹² Present address: Argonne National Laboratory, 9700 Cass Ave, Lemont, IL, 60439, USA

^* e-mail: andrej.herzan@savba.sk

Received: 12 March 2020
Accepted: 17 May 2020
Published online: 10 June 2020

Abstract

High-spin states of the odd–odd ${}^{194}$ Bi nucleus have been studied by means of nuclear spectroscopy for the first time. Two low-lying rotational bands were observed. The positive-parity band built on a short-lived isomeric state 633 keV above the $\alpha$ and $\beta$ decaying long-lived (10 $$^-$$ ) state is assigned a ${\pi i_{13/2} \otimes \nu i_{13/2 }^{-1}}$ configuration, while the other band is attributed to the ${\pi h_{9/2} \otimes \nu i_{13/2 }^{-1}}$ configuration. Both of these bands are assumed to have oblate shape. Three band-like structures composed predominantly of $\Delta I = 1$ transitions were also found. One of the shears band candidates is firmly linked to the lower lying level structures whereas for the other two links to lower-lying structures remain missing.