Four-body DWBA calculations of the Coulomb breakup of He-6

We investigate the Coulomb breakup of the two-neutron-halo nucleus He-6 by extending the framework of the finite-range postform. distorted-wave Born a pproximation theory introduced earlier for the description of the breakup o f one-neutron-halo nuclei. The model can use the realistic three-body wave function for the He-6 ground state. Calculations have been performed for en ergy, total and parallel momentum distributions of He-4 fragment. The two-b ody He-4-neutron and neutron-neutron correlations have also been calculated . Our results are compared with those of an adiabatic model of the Coulomb- breakup reactions. The two theories lead to almost identical results. Compa risons are also made with the available experimental data. It is found that the pure Coulomb breakup can describe the bulk of the data taken at below grazing angles. However. a rigorous description of all the available data r equires the consideration of the nuclear-breakup effects. (C) 2001 Elsevier Science B.V. All rights reserved.