arXiv:1606.09057·v1·Nuclear Experiment
First Measurement of Collectivity of Coexisting Shapes based on Type II Shell Evolution: The Case of Zr
C. Kremer · S. Aslanidou · S. Bassauer · M. Hilcker · A. Krugmann · P. von Neumann-Cosel · T. Otsuka · N. Pietralla · V. Yu. Ponomarev · N. Shimizu · M. Singer · G. Steinhilber
Abstract
Background: Type II shell evolution has recently been identified as a microscopic cause for nuclear shape coexistence. Purpose: Establish a low-lying rotational band in 96-Zr. Methods: High-resolution inelastic electron scattering and a relative analysis of transition strengths are used. Results: The B(E2; 0_1^+ -> 2_2^+) value is measured and electromagnetic decay strengths of the secdond 2^+ state are deduced. Conclusions: Shape coexistence is established for 96-Zr. Type II shell evolution provides a systematic and quantitative mechanism to understand deformation at low excitation energies.
Comments: 5 pages, 4 figures