To identify the states of the 0 ϩ , 2 ϩ , 4 ϩ , and 6 ϩ two octupole phonon ͑TOP͒ multiplet in 208 Pb and their respective fragmentation inelastic proton, deuteron, and ␣ scattering has been measured in high energy resolution. Quantum numbers and spectroscopic factors of excited states up to 8 MeV are obtained from the 207 Pb(d,p) 208 Pb transfer reaction with vector polarized deuterons. From the comparison with literature, we conclude that up to E x ϭ6 MeV, essentially all states are resolved. The data are compared with recent calculations within the quasiparticle phonon model. For the lowest states the calculated energies are in excellent agreement with experiment. The calculated spectrum of 0 ϩ , 2 ϩ , 4 ϩ , and 6 ϩ states, which includes mixing with the TOP multiplet, is related to experimental states up to excitation energies above twice the excitation energy of the collective 3 1Ϫ state at E x ϭ5230 keV. The measured excitation strengths are consistent with the predicted fragmentation of the two octupole phonon states.

A new high-precision (p,t) study of the 158 Gd nucleus was carried out with the Q3D spectrometer at the University of Munich. The result is the observation for the first time of a deformed nucleus with 13 excited 0 ϩ states below an excitation energy of approximately 3.1 MeV. Seven of these 0 ϩ states are observed for the first time and an additional three are new confirmations of previous tentative assignments. This abundance of 0 ϩ states provides significant new information on these poorly understood excitations. 158 Gd can now be viewed as a unique laboratory for further investigations on the nature of 0 ϩ excitations in nuclei.The nature of low lying K ϭ0 ϩ bands in deformed nuclei remains a mystery. Traditionally the first excited K ϭ0 ϩ bands along with the K ϭ2 ϩ bands were labeled as single-phonon ''␤'' and ''␥'' vibrational excitations. The K ϭ2 ϩ excitations are well understood theoretically and shown to vary smoothly in collectivity across a given isotopic chain ͓1-3͔. The nature of K ϭ0 ϩ excitations however still remains enigmatic and therefore the focus of intense discussions as well as a flurry of activity from both theoretical and experimental aspects. Data on K ϭ0 ϩ bands have traditionally been relatively sparse. However, recent improvements in technology have remedied the situation by enabling spectroscopy, reaction, and lifetime measurements of a large number of K ϭ0 ϩ bands that were previously inaccessible in nuclei.The results are puzzling at best. First, in many deformed nuclei of the rare-earth region, there are several excited K ϭ0 ϩ bands below the pairing gap. Second, there are variations in collectivity amongst the K ϭ0 ϩ bands in the same nucleus, as well as enormous variations in collectivity of the first excited K ϭ0 ϩ bands in very narrow isotopic regions.Numerous attempts have been made to address the nature of low-lying K ϭ0 ϩ bands via various nuclear models. The IBM and the newly developed critical point symmetries ͓4 -6͔ or partial dyamical symmetries ͓7,8͔ are amongst the newest approaches as well as the more traditional QPNM ͓9͔ ͑quasi-particle-phonon nuclear model͒.The microscopic calculations of Soloviev et al. within the QPNM ͓9͔ yield a Hamiltonian of phonons, quasiparticles ͑qp͒, and phonon-qp interactions. Calculations have been done for several rare-earth deformed nuclei and in each case, the result is a spectrum that typically includes five excited K ϭ0 ϩ bands below 2.3 MeV. The exact nature of these K ϭ0 ϩ bands then depends on the number of phonons and qp pairs included.A review of existing data and a discussion of several possible interpretations is given in Ref. ͓10͔. Suffice it to say that K ϭ0 ϩ bands are one of the fundamental excitations in nuclear spectra and their nature is not yet fully understood. The numerous recent publications addressing this subject point to the immense current interest on this topic. In order to carry out a meaningful discussion or a comprehensive theoretical effort to understand the nature of these K ϭ0 ϩ bands, it is first nece...

Experimental Evidence for Hyperdeformed States in U IsotopesKrasznahorkayGeneral rights Copyright and moral rights for the publications made accessible in the public portal are retained by the authors and/or other copyright owners and it is a condition of accessing publications that users recognise and abide by the legal requirements associated with these rights.• Users may download and print one copy of any publication from the public portal for the purpose of private study or research.• You may not further distribute the material or use it for any profit-making activity or commercial gain • You may freely distribute the URL identifying the publication in the public portal Take down policy If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim. VOLUME 80, NUMBER 10 P H Y S I C A L R E V I E W L E T T E R S 9 MARCH 1998 Experimental Evidence for Hyperdeformed States in U Isotopes

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The catalytic synthesis of linear α-olefins from ethylene is a technologically highly important reaction. A synthesis concept allowing the formation of selective products and various linear α-olefin product distributions with one catalyst system is highly desirable. Here, we describe a trimetallic catalyst system (Y–Al–Ni) consisting of a rare earth metal polymerization catalyst which can mediate coordinative chain transfer to triethylaluminum combined with a simultaneously operating nickel β-hydride elimination/transfer catalyst. This nickel catalyst displaces the grown alkyl chains forming linear α-olefins and recycles the aluminum-based chain transfer agent. With one catalyst system, we can synthesize product spectra ranging from selective 1-butene formation to α-olefin distributions centered at 850 gmol−1 with a low polydispersity. The key to this highly flexible linear α-olefin synthesis is the easy tuning of the rates of the Y and Ni catalysis independently of each other. The reaction is substoichiometric or formally catalytic regarding the chain transfer agent.