Coulomb Breakup Reactions in Complex-Scaled Solutions of the Lippmann-Schwinger Equation

We propose a new method to describe three-body breakups of nuclei, in which the Lippmann-Schwinger equation is solved in combination with the complex scaling method. The complex-scaled solutions of the Lippmann-Schwinger equation (CSLS) enable us to treat boundary conditions of many-body open channels correctly and to describe a many-body breakup amplitude from the ground state. The Coulomb breakup cross section from the He-6 ground state into He-4+n+n three-body decaying states as a function of the total excitation energy is calculated using CSLS, and the result well reproduces the experimental data. Furthermore, the two-dimensional energy distribution of the El transition strength is obtained and the importance of the He-5(3/2(-)) resonance is confirmed. It is shown that CSLS is a promising method to investigate correlations of subsystems in three-body breakup reactions of weakly bound nuclei.