1. Comprehensive Test of the Brink-Axel Hypothesis in the Energy Region of the Pygmy Dipole Resonance
- Author
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H. C. Berg, D. Gjestvang, Achim Richter, L. G. Pedersen, P. Scholz, Sunniva Siem, M. Guttormsen, Johann Isaak, E. Sahin, M. Markova, André Larsen, S. Bassauer, W. Paulsen, F. L. Bello Garrote, M. Mbabane, Gry Merete Tveten, Andreas Görgen, T. K. Eriksen, M. M. Bjørøen, Fabio Zeiser, T. Dahl-Jacobsen, V. M. Valsdottir, P. von Neumann-Cosel, M. Wiedeking, and N. I. J. Pettersen
- Subjects
Physics ,Nuclear Theory ,Spins ,010308 nuclear & particles physics ,FOS: Physical sciences ,General Physics and Astronomy ,01 natural sciences ,Resonance (particle physics) ,Spectral line ,Nuclear Theory (nucl-th) ,Nuclear physics ,Dipole ,0103 physical sciences ,Neutron ,Nuclear Experiment (nucl-ex) ,Nuclear Experiment ,010306 general physics ,Beam (structure) ,Energy (signal processing) ,Excitation - Abstract
The validity of the Brink-Axel hypothesis, which is especially important for numerous astrophysical calculations, is addressed for 116,120,124Sn below the neutron separation energy by means of three independent experimental methods. The $\gamma$-ray strength functions (GSFs) extracted from primary $\gamma$-decay spectra following charged-particle reactions with the Oslo method and with the Shape method demonstrate excellent agreement with those deduced from forward-angle inelastic proton scattering at relativistic beam energies. In addition, the GSFs are shown to be independent of excitation energies and spins of the initial and final states. The results provide a critical test of the generalized Brink-Axel hypothesis in heavy nuclei, demonstrating its applicability in the energy region of the pygmy dipole resonance., Comment: 6 pages, 4 figures, Phys. Rev. Lett. (in press)
- Published
- 2021
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