Nuclear Physics A556 ( 1993) 26 I-280 Noah-Holland Coulomb excitation of 226Ra H.J. Wollersheim, HI. Emling, H. Grein, R. Kulessa’ and R.S. Simon ~~s~f~s~~uf# fiir Schwerjo~enforsch~~g, ~ar~stadt, Germany C. F~e~scbrn~n~, J. de Boer, E. Hauber, C. ~a~terbacb and C. Schandera ~e~~j~~ ~~ysi~~ Lrtdwig-~rxi~Plin_Universitiit, ~~~j~h, Germany PA. Butler Qiiver Lodge Laboratory, University of Liverpool, Liverpool, UK T. Czosnyka SLCJ, University of Warsaw, Warsaw, Poland Received 30 May 1992 (Revised 14 September 1992) Abstract: Radioactive targets of ““Ra were Coulomb excited by ‘He projectiles (particle spectroscopy~, and %, 32S and *e’Fb projectiles (particle-y coincidences}. The K =#* rotational bands could be followed up to spin 18* and 17-, respectively. All experiments were simultaneously analyzed in terms of Et, EL?, E3 and E4 matrix elements coupling the positive- and negative-parity rotational states. The systematics of level energies, as well as dipole, quadrupofe and octupole matrix eiements are discussed in the framework of models assuming stable octupole deformation. E Evidence has increased during the Iast few years that certain nuclei can he described in terms of intrinsic shapes with party-break~~g static moments. In particular, the discovery ‘) of very low-lying 1.. states in the light actinides has led to the suggestion of stable octupole deformations. It has been recognized “) that the microscopic origin for the occurrence of this structure lies in the coupling between single-particle states which differ by Al = 3 and Aj = 3. These states lie close to each other and to the Fermi surface at proton and neutron numbers near 34, 56, 88 and 134 where octupole correlations are expected to be strongest. Fig. zyxwvutsrqponmlkjihgfed 1 (top) shows Correspondence to: Dr. H.J. Wollersheim, GSI, Postfach 110 552, D-6100 Darmstadt 11, Germany. ’ Permanent address: Jag~l~onia~ ~~iversity~ Cracow, Poland. 0375-94?4/93~~~.~~ @I 1993 - Elsevier Science ~bl~she~ B.V. All rights reserved