Neutron density distribution and the halo structure ofC22

Abstract

The recently measured reaction cross sections for the neutron-rich carbon isotopes ($^{19}\mathrm{C}$, $^{20}\mathrm{C}$, and $^{22}\mathrm{C}$) on a proton target at 40 A MeV are analyzed using the finite range Glauber model (FRGM) and the microscopic optical potential calculated within the Brueckner-Hartree-Fock formalism (BHF). In FRGM nucleon-nucleon cross sections are used, while in the latter (BHF), Hamada-Johnston, Urbana v-14, and the Argonne v-18 internucleon potentials are employed to calculate the microscopic optical potential. The required nucleon density distributions are calculated within the relativistic mean-field (RMF) framework. To test the halo structure, the extended neutron density distribution for $^{22}\mathrm{C}$ is also used. The analysis reveals that the BHF results of all three internucleon potentials are very close to each other, and also agree with the corresponding results of the FRGM. Our results, using RMF densities, are in agreement with the experimental data for all isotopes of carbon except $^{22}\mathrm{C}$, for which we require extended neutron density distribution, indicating a halo structure.