1. Gamma decay of the $^{154}$Sm Isovector Giant Dipole Resonance: Smekal-Raman Scattering as a Novel Probe of Nuclear Ground-State Deformation
- Author
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Kleemann, J., Pietralla, N., Friman-Gayer, U., Isaak, J., Papst, O., Prifti, K., Werner, V., Ayangeakaa, A. D., Beck, T., Colò, G., Cortés, M. L., Finch, S. W., Fulghieri, M., Gribble, D., Ide, K. E., James, X. K. -H., Janssens, R. V. F., Johnson, S. R., Koseoglou, P., Krishichayan, Savran, D., and Tornow, W.
- Subjects
Nuclear Experiment ,Nuclear Theory - Abstract
The $\gamma$ decays of the Isovector Giant Dipole Resonance (GDR) of the deformed nucleus $^{154}$Sm from $2^+_1$-Smekal-Raman and elastic scattering were measured using linearly polarized, quasi-monochromatic photon beams. The two scattering processes were disentangled through their distinct angular distributions. Their branching ratio and cross sections were determined at six excitation energies covering the $^{154}$Sm GDR. Both agree with the predictions of the geometrical model for the GDR and establish $\gamma$ decay as an observable sensitive to the structure of the resonance. Consequently, the data place strong constraints on the nuclear shape, including the degree of triaxiality. The derived $^{154}$Sm shape parameters $\beta=0.2926(26)$ and $\gamma=5.0(14)$ agree well with other measurements and recent Monte Carlo Shell-Model calculations., Comment: 7 pages, 3 figures, 3 tables
- Published
- 2024