1. Collective excitations of 96Ru by means of (p, p'γ) experiments.
- Author
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Hennig, A., Ahn, T., Anagnostatou, V., Blazhev, A., Cooper, N., Derya, V., Elvers, M., Endres, J., Goddard, P., Heinz, A., Hughes, R. O., Ilie, G., Mineva, M. N., Petkov, P., Pickstone, S. G., Pietralla, N., Radeck, D., Ross, T. J., Savran, D., and Spieker, M.
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PHONON-phonon interactions , *QUADRUPOLES , *INELASTIC scattering , *NUCLEAR excitation , *NUCLEAR shell theory ,RUTHENIUM isotopes - Abstract
Background: One-phonon mixed-symmetry quadrupole excitations are a well-known feature of near-spherical, vibrational nuclei. Their interpretation as a fundamental building block of vibrational structures is supported by the identification of multiphonon states resulting from a coupling of fully-symmetric and mixed-symmetric quadrupole phonons. In addition, the observation of strong M1 transitions between low-lying 3- and 4+ states has been interpreted as an evidence for one-phonon mixed-symmetry excitations of octupole and hexadecapole character. Purpose: The aim of the present study is to identify collective one- and two-phonon excitations in the heaviest stable N = 52 isotone 96Ru based on a measurement of absolute Ail, E1, and E2 transition strengths. Methods: Inelastic proton-scattering experiments have been performed at the Wright Nuclear Structure Laboratory (WNSL), Yale University, and the Institute for Nuclear Physics (IKP), University of Cologne. From the acquired proton-γ and γγ coincidence data we deduced spins of excited states, y-decay branching ratios, and multipole mixing ratios, as well as lifetimes of excited states via the Doppler-shift attenuation method (DSAM). Results: Based on the new experimental data on absolute transition strengths, we identified the 2+ and 3+ members of the two-phonon mixed-symmetry quintuplet (21ms+⊙21ms+).Furthermore, we observed strong M1 transitions between low-lying 3- and 4+ states suggesting one-phonon symmetric and mixed-symmetric octupole and hexadecapole components in their wave functions, respectively. The experimental results are compared to sdg-IBM-2 and shell-model calculations. Conclusions: Both the sdg-IBM-2 and the shell-model calculations are able to describe key features of mixed-symmetry excitations of 96Ru. Moreover, they support the one-phonon mixed-symmetry hexadecapole assignment of the experimental 42+ state. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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