RADII OF CLUSTER STATES IN 11B AND 13C

Differential cross sections of the inelastic deuterons, 3He and α-particle scattering on 11B and 13C at the incident energies ~ 10 - 100 MeV/u were analyzed in the diffraction angular range. It was shown that the excited states 3/2- (8.56 MeV) of 11B and 1/2- (8.86, 11.08 and 12.5 MeV) of 13C which are located close to the 2α + t and 3α + n thresholds correspondingly, have the radii enhanced by a factor ~ 1.2 in comparison with those of the ground states. Their values are approximately equal to the value of the 12C radius in the excited state 7.65 MeV (Hoyle state) and are close to predictions of different versions of antisymmetrized molecular dynamics (AMD) model.