Cluster states in 11B and 13C

The cluster structures of the excited states in 11B and 13C were discussed by measuring the isoscalar monopole strengths in the inelastic α scattering at Eα = 388 MeV. It was found that the 1/22−, 1/23−, and 1/24− states in 13C are candidates for the α cluster states with a 3α + n molecular configuration.