Gießen 2007 – scientific programme

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HK: Fachverband Physik der Hadronen und Kerne

HK 49: Poster

HK 49.15: Poster

Thursday, March 15, 2007, 16:00–17:00, P

E0 Transitions in Rare Earth Isotopes ¹⁵⁴Sm and ¹⁶⁶Er — •K. Wimmer^1,4, V. Bildstein^2,4, R. Gernhäuser^2,4, D. Habs^1,4, C. Hinke^2,4, H. Hübel³, T. Kröll^2,4, R. Krücken^2,4, R. Lutter^1,4, H.J. Maier^1,4, P. Maierbeck^2,4, T. Morgan^1,4, W. Schwerdtfeger^1,4, and P. Thirolf^1,4 — ¹Department für Physik, Ludwig Maximilians Universität München — ²Physik-Department E12, Technische Universität München — ³Rheinische Friedrich-Wilhelms-Universität Bonn — ⁴Maier-Leibnitz-Laboratory, Garching

So far little experimental data is available on E0 matrix elements in shape transitional (spherical to deformed) regions of the chart of nuclei. Calculations using the interacting-boson approximation (IBA) predict a sharp increase in the monopole strength ρ²(E0;0₂⁺→ 0₁⁺) in this phase transitional regime (in agreement with experimental data), which then remains large for well deformed nuclei which is not yet confirmed [1]. Excited states in ¹⁵⁴Sm and ¹⁶⁶Er were populated via safe Coulomb excitation using self-supporting targets (760 and 995 µg/cm²) and an ¹⁶O beam at the MLL (E_lab=60 and 55 MeV). Scattered particles were detected in a 64-fold segmented DSSSD in backward direction, while the electrons were registered in a cooled Si(Li) detector in conjunction with a Mini-Orange spectrometer. Simultaneously the γ-rays emitted by the excited nuclei were detected with a Germanium Miniball cluster-detector. In ¹⁵⁴Sm the E0 transition from the first excited 0⁺ state could be identified and further results of the analysis will be presented.

[1] P. von Brentano et al., Phys. Rev. Lett. 93, 152502 (2004)