Reaction cross sections forB8,Be7, andLi6+Ni58near the Coulomb barrier: Proton-halo effects

Abstract

Elastic scattering of ${}^8\mathrm{B}$, ${}^7\mathrm{Be}$, and ${}^6\mathrm{Li}$ on a ${}^{58}\mathrm{Ni}$ target has been measured at energies near the Coulomb barrier. Optical-model fits were made to the experimental angular distributions, and total reaction cross sections were deduced. A comparison with other systems provides striking evidence for proton-halo effects on ${}^8\mathrm{B}$ reactions. As opposed to the situation for the neutron-halo nucleus ${}^6\mathrm{He}$, for which particle transfer dominates, the “extra” cross section observed for ${}^8\mathrm{B}$ appears to result entirely from projectile breakup.