Density distribution of 17B from a reaction cross-section measurement -: art. no. 054320

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