Density distribution ofB17from a reaction cross-section measurement

Abstract

The reaction cross section ({sigma}{sub R}) for the neutron-rich nucleus {sup 17}B on a carbon target has been measured at an energy of 77A MeV by the transmission method. An enhancement of {sigma}{sub R} at intermediate energy compared to that at high energy was observed. The density distribution of {sup 17}B was deduced through the energy dependence of {sigma}{sub R} using a finite-range Glauber-type calculation under an optical-limit approximation as well as a few-body approach. The existence of a long neutron tail in {sup 17}B was demonstrated. The fraction of the wave function with the valence two-neutron configuration of (2s{sub 1/2}){sub J=0}{sup 2} or (1d{sub 5/2}){sub J=0}{sup 2} was found to be 50{+-}10% based on a finite-range few-body Glauber-type calculation.