Contrasting Behavior in Octupole Structures Observed at High Spin in <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow></mrow><mrow><mn>220</mn></mrow></msup></mrow></math></span>Ra and <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mrow><msup><mrow></mrow><mrow><mn>222</mn></mrow></msup></mrow></math></span>Th

J. F. Smith; J. F. C. Cocks; N. Schulz; M. Aïche; M. Bentaleb; P. A. Butler; F. Hannachi; G. D. Jones; P. M. Jones; R. Julin; S. Juutinen; R. Kulessa; E. Lubkiewicz; A. Płochocki; F. Riess; E. Ruchowska; A. Savelius; J. C. Sens; J. Simpson; E. Wolf

doi:10.1103/PhysRevLett.75.1050

Contrasting Behavior in Octupole Structures Observed at High Spin in $^{220}$ Ra and $^{222}$ Th

J. F. Smith, J. F. C. Cocks, N. Schulz, M. Aïche, M. Bentaleb, P. A. Butler, F. Hannachi, G. D. Jones, P. M. Jones, R. Julin, S. Juutinen, R. Kulessa, E. Lubkiewicz, A. Płochocki, F. Riess, E. Ruchowska, A. Savelius, J. C. Sens, J. Simpson, and E. Wolf

Phys. Rev. Lett. 75, 1050 – Published 7 August 1995

Abstract

Alternating-parity states connected by strong $E 1$ transitions, characteristic of a reflection-asymmetric rotor, have been observed to high spins in the isotones $^{220}$ Ra and $^{222}$ Th. This level structure is observed up to $J^{π} {= 29}^{-} (31^{-})$ in $^{220}$ Ra while it cannot be seen beyond $J^{+} {= 24}^{+} (25^{-})$ in $^{222}$ Th. These observations are consistent with Woods-Saxon-Bogolyubov cranking calculations which predict that the yrast band of $^{222}$ Th will undergo a shape transition at $J = 24 ħ$ , in contrast to that of $^{220}$ Ra which maintains its reflection asymmetry to higher spins.

Received 2 March 1995

DOI:https://doi.org/10.1103/PhysRevLett.75.1050

Authors & Affiliations

J. F. Smith¹, J. F. C. Cocks¹, N. Schulz², M. Aïche³, M. Bentaleb², P. A. Butler¹, F. Hannachi³, G. D. Jones¹, P. M. Jones¹, R. Julin⁴, S. Juutinen⁴, R. Kulessa⁵, E. Lubkiewicz⁵, A. Płochocki⁶, F. Riess⁷, E. Ruchowska⁶, A. Savelius⁴, J. C. Sens², J. Simpson⁸, and E. Wolf⁷

¹Oliver Lodge Laboratory, University of Liverpool, L69 3BX, United Kingdom
²Centre de Recherches Nucléaires, IN2P3, Université Louis Pasteur, F-67037, Strasbourg, France
³Centre de Spectrométrie Nucléaire et de Spectrométrie de Masse, IN2P3-CNRS, F-91405, Orsay, France
⁴Accelerator Laboratory, University of Jyväskylä, FIN-40351, Jyväsylä, Finland
⁵Institute of Physics, Jagellonian University, 30-059 Cracow, Poland
⁶University of Warsaw, Hoża 69, PL-00-681, Warsaw, Poland
⁷Sektion Physik der Universität München, D-85748 Garching, Germany
⁸DRAL, Daresbury Laboratory, Daresbury, Warrington, WA4 4AD, United Kingdom