One-neutron halo structure inC15

Abstract

The one- or two-neutron removal reactions as well as reaction cross sections for C-14,C-15 on carbon target have been studied by using 110A MeV Ne-22 primary beam on Riken Projectile Fragment Separator in RIKEN. The longitudinal momentum distributions of C-13,C-14 fragments from C-15 and C-13 fragments from C-14 breakup have been measured at 83A MeV by means of direct time-of-flight method. Full width at half maximum (FWHM) of the distributions have been determined to be 71+/-9 MeV/c and 223+/-28 MeV/c for C-14 and C-13 from C-15, and 195+/-21 MeV/c for C-13 from C-14. The FWHM for C-13 fragments from C-15 and C-14 breakup are consistent with the Goldhaber model's prediction. While the FWHM of C-14 fragments from C-15 is much smaller, which confirms the experimental results from MSU and GANIL, an anomalous enhancement from its neighbors has been observed in the measured reaction cross section of C-15. The experimental data are discussed in the framework of the Glauber model. The analysis of both the fragment momentum distributions and reaction cross sections indicates a dominant s-wave component in the ground state of C-15.