Coulomb breakup mechanism of neutron-halo nuclei in a time-dependent method

The mechanism of the Coulomb breakup reactions of the nuclei with neutron-halo structure is investigated in detail. A time-dependent Schrodinger equation for the halo neutron is numerically solved by treating the Coulomb field of a target as an external field. The momentum distribution and the post-acceleration effect of the final fragments are discussed in a fully quantum mechanical way to clarify the limitation of the intuitive picture based on the classical mechanics. The theory is applied to the Coulomb breakup reaction of Be-11+ Pb-208. The breakup mechanism is found to be different between the channels of j(pi) = 1/2(-) and 3/2(-), reflecting the underlying structure of Be-11. The calculated result reproduces the energy spectrum of the breakup fragments reasonably well, but explains only about a half of the observed longitudinal momentum difference.