High-spin structure of the neutron-rich odd-odd $\chem{^{106,108}_{\quad\; \ 45}Rh}$ and $\chem{^{110,112}_{\quad\ \; 47}Ag}$ isotopes

M.-G. Porquet; Ts. Venkova; P. Petkov; A. Bauchet; I. Deloncle; A. Astier; N. Buforn; J. Duprat; B.J.P. Gall; C. Gautherin; E. Gueorguieva; F. Hoellinger; T. Kutsarova; R. Lucas; M. Meyer; A. Minkova; N. Redon; N. Schulz; H. Sergolle; A. Wilson

doi:doi:10.1140/epja/i2001-10269-9

2022 Impact factor 2.7

Hadrons and Nuclei

Eur. Phys. J. A 15, 463-470 (2002)
DOI: 10.1140/epja/i2001-10269-9

High-spin structure of the neutron-rich odd-odd $\chem{^{106,108}_{\quad\; \ 45}Rh}$ and $\chem{^{110,112}_{\quad\ \; 47}Ag}$ isotopes

M.-G. Porquet¹, Ts. Venkova², P. Petkov², A. Bauchet¹, I. Deloncle¹, A. Astier³, N. Buforn³, J. Duprat^{4, 1}, B.J.P. Gall⁵, C. Gautherin⁶, E. Gueorguieva⁷, F. Hoellinger⁵, T. Kutsarova², R. Lucas⁶, M. Meyer³, A. Minkova⁷, N. Redon³, N. Schulz⁵, H. Sergolle⁴ and A. Wilson¹

¹ CSNSM, IN2P3/CNRS and Université Paris-Sud, F-91405 Orsay Campus, France
² INRNE, BAS, 1784 Sofia, Bulgaria
³ IPNL, IN2P3/CNRS and Université Claude Bernard, F-69622 Villeurbanne, France
⁴ IPN, IN2P3/CNRS and Université Paris-Sud, F-91406 Orsay, France
⁵ IReS, IN2P3/CNRS and Université Louis Pasteur, F-67037 Strasbourg Cedex 2, France
⁶ DAPNIA/SPhN, CEA Saclay, F-91191 Gif-sur-Yvette, France
⁷ University of Sofia, Faculty of Physics, 1126 Sofia, Bulgaria

porquet@csnsm.in2p3.fr

(Received: 1 June 2001 / Revised version: 15 July 2002 / Published online: 10 December 2002)

Abstract
The $\chem{^{106,108}Rh}$ and $\chem{^{110,112}Ag}$ nuclei have been produced as fission fragments following the fusion reaction $\chem{^{28}Si}$ + $\chem{^{176}Yb}$ at 145 MeV bombarding energy and studied with the Eurogam2 array. The yrast high-spin states of these four odd-odd nuclei, which are observed for the first time, consist of rotational bands in which the odd proton occupies the $\pi g_{9/2}$ subshell and the odd neutron the $\nu h_{11/2}$ subshell. Their behaviour as a function of spin values does not vary with the number of neutrons: as observed in the odd- N neighbouring nuclei, the motion of the odd neutron remains decoupled from the motion of the core, from N = 61 to N = 65. Moreover, the staggering observed in the yrast bands of odd-odd isotopes is strongly reduced as compared to the large values displayed by the rotational bands built on the $\pi g_{9/2}$ subshell in the odd- A Rh and Ag isotopes. The results of particle-rotor calculations indicate that this reduction is related to a change of the core deformation.

PACS
21.60.Ev - Collective models.
23.20.Lv - Gamma transitions and level energies.
25.85.Ge - Charged-particle-induced fission.
27.60.+j - $90 \leq A \leq 149$ .

© Società Italiana di Fisica, Springer-Verlag 2002