Rotational bands in 11B and identification of diluted states

21st International School on Nuclear Physics and Applications & International Symposium on Exotic Nuclei

Demyanova, A.S.^1 ; Danilov, A.N.^1 ; Ogloblin, A.A.^1 ; Goncharov, S.A.^2 ; Belyaeva, T.L.^3 ; Trzaska, W.^4

National Research Centre Kurchatov Institute, Moscow

123182, Russia^1

Lomonosov Moscow State University, Moscow

119991, Russia^2

Universidad Autonoma Del Estado de Mexico, Toluca

50000, Mexico^3

JYFL, Jyvaskyla

FIN-40500, Finland^4

关键词: Cluster structure;    Differential cross section;    Diffraction modeling;    Low-lying state;    Moment of inertia;    Moments of inertia;    Root mean square radius;    Shell structure;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/724/1/012013/pdf
DOI  :  10.1088/1742-6596/724/1/012013

来源: IOP

【 摘 要 】

Differential cross-sections of the11B + α inelastic scattering at E(α) = 65 leading to the most of the known11B states at the excitation energies up to 14 MeV were measured. The data analysis was done by DWBA and in some cases by the modified diffraction model allowing determining the radii of the excited states. The radii of the states with excitation energies less than ∼ 7 MeV with the accuracy not less than 0.1-0.15 fm coincide with the radius of the ground state. This result is consistent with the traditional view of the shell structure of the low-lying states in11B. Most of the observed high-energy excited states are distributed among four rotational bands. The moments of inertia of band states are close to the moment of inertia of the Hoyle state of12C. The calculated radii, related to these bands, are 0.7 - 1.0 fm larger than the radius of the ground state, and are close to the radius of the Hoyle state. These results are in agreement with existing predictions about various cluster structure of11B at high excitation energies. The state with the excitation energy 12.56 MeV, Iπ= 1/2+, T = 1/2 and the root mean square radius R ∼ 6 fm predicted in the frame of the alpha condensate hypothesis was not found.