Nuclear states with anomalously large radius (size isomers)

Abstract

Methods of determination of the nuclear excited state radii are discussed together with the recently obtained data on the states of some light nuclei having abnormally large radii (size isomers). It is shown that such states include excited neutron-halo states in ⁹Be, ¹¹Be, and ¹³C and some alpha-cluster states in ¹²C, ¹¹B, and ¹³C. Among the latter ones, there is the well-known Hoyle state in ¹²C—the structure of this state exhibit rudimentary features of alpha-particle states.