Cluster rotational bands in11B

A.N Danilov,A.A Ogloblin,S.A Goncharov,T.L Belyaeva,A.S Demyanova,W Trzaska

doi:10.1051/epjconf/201611704011

Abstract

Differential cross-sections of 11 B+α inelastic scattering at E (α ) =65 MeV leading to most of the known 11 B states at excitation energies up to 14 MeV were measured [1]. The data analysis was done using Modified diffraction model (MDM) [2] allowing determining radii of excited states. Radii of the states with excitation energies less than ∼ 7 MeV coincide with the radius of the ground state with an accuracy not less than 0.1 - 0.15 fm. This result is consistent with traditional view on shell structure of low-lying states in 11 B. Most of the observed high-energy excited states are distributed among four rotational bands. Moments of inertia of band states are close to the moment of inertia of the Hoyle state of 12 C. 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 Hoyle state radius. These results are in agreement with existing predictions about various cluster structure of 11 B at high excitation energies.

Highlights

During long time 11B nucleus was considered as a good example of shell effects in light nuclei
Up to excitation energies ∼ 7 MeV 11B states were described by different variants of shell models
With excitation energy 8.56 MeV, which is not described by any variant of the shell model

Summary

Introduction

During long time 11B nucleus was considered as a good example of shell effects in light nuclei. Up to excitation energies ∼ 7 MeV 11B states were described by different variants of shell models. One of the main suggestions of this theory is abnormally large radius of the Hoyle state. With excitation energy 8.56 MeV, which is not described by any variant of the shell model.

Results

Conclusion