# Approaching complete low-spin spectroscopy of $^{210}$Bi with a cold-neutron capture reaction

Abstract : The low-spin structure of the 210Bi nucleus was investigated in the neutron capture experiment 209Bi(n,γ )210Bi performed at ILL Grenoble at the PF1B cold-neutron facility. By using the EXILL multidetector array, consisting of 46 high-purity germanium crystals, and γγ-coincidence technique, 64 primary γ rays were observed (40 new) and a total number of 70 discrete states (33 new) were located below the neutron binding energy in 210Bi. The analysis of the angular correlations of γ rays provided information about transitions multipolarities, which made it possible to confirm most of the previously known spin-parity assignments and helped establish new ones. The obtained experimental results were compared to shell-model calculations involving one-valence-proton, one-valence-neutron excitations outside the 208Pb core. It has been found that while up to the energy of ∼2 MeV each state observed in 210Bi has its calculated counterpart; at higher excitation energies some levels cannot be described by the valence particle couplings. These states may arise from couplings of valence particles to the 3− octupole phonon of the doubly magic 208Pb core and may serve as a testing ground for models which describe single particle-phonon excitations.
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Journal articles

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Submitted on : Tuesday, May 3, 2016 - 10:07:01 AM
Last modification on : Tuesday, May 22, 2018 - 9:48:11 PM

### Citation

N. Cieplicka-Oryńczak, B. Fornal, S. Leoni, D. Bazzacco, A. Blanc, et al.. Approaching complete low-spin spectroscopy of $^{210}$Bi with a cold-neutron capture reaction. Physical Review C, American Physical Society, 2016, 93 (5), pp.054302. ⟨10.1103/PhysRevC.93.054302⟩. ⟨in2p3-01310737⟩

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