Halo Structure of Nucleus ²³ Al

Abstract

The recently measured reaction cross section of 23Al is analysed in the Glauber model with an optical limit or few-body approach. It is found that the conventional fixed core-plus-nucleon model for halo nuclei is unable to explain the observed abnormally large reaction cross section of 23Al by any selection of the halo nucleon configurations. The reaction cross section of 23Al can be described when the core size is enlarged, although the Coulomb barrier largely hinders the formation of a halo structure for proton-rich nuclei. This is consistent with the case in s-d shell neutron-rich nuclei, where an enlarged core was proposed to explain both the reaction cross section and longitudinal momentum distribution data.