Tests of the discretized-continuum method in three-body dipole strengths

Comparative Study of Three-Body Models for Continuum States

“…As already observed in Ref. 19) for the pseudostate method, the energy dependences are very similar but the amplitude is systematically smaller with the projection technique. This is essentially due to the ground-state wave function which presents a smaller amplitude at large distances with the projection method.…”

“…This technique is widely used in coupled-channel calculations, 9) or in the calculations of dipole strengths in halo nuclei. 19), 31) The continuum is discretized over a finite basis as 11) and approximate scattering wave functions are determined at some positive (and real) energies E λ . Of course these eigenvalues depend on the basis, and are available at some energies only.…”

“…In Ref. 19) we have shown that the smeared E1 distributions are rather sensitive to this choice. The R-matrix method and the CSM provide continuous distributions.…”

“…In contrast, the PS approach requires the introduction of this parameter, and its choice is partly ambiguous. 19) In the next section, the three methods are applied to the 6 He dipole distribution. §5.…”

“…This method has been extensively used to describe resonances, but recent developments also deal with scattering matrices 17) and dipole-strength distributions. 16) The pseudostate (PS) method 18), 19) can be seen as a further simplification of the CSM. The scattering wave functions are approximated by square-integrable functions defined at discrete (positive) energies.…”