Cluster rotational bands in ¹¹B

¹ National Research Center ‘Kurchatov Institute’, Moscow, 123182, Russia
² Universidad Autonoma del Estado de Mexico, Toluca, 50000, Mexico
³ Lomonosov Moscow State University, Moscow, 119991, Russia
⁴ JYFL, Jyväskylä, FIN-40500, Finland

Published online: 11 May 2016

Abstract

Differential cross-sections of ¹¹B+α inelastic scattering at E(α) =65 MeV leading to most of the known ¹¹B 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 ¹¹B. 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 ¹²C. 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 ¹¹B at high excitation energies.