A non-perturbative approach to halo breakup

The theory of weakly bound cluster breakup, like halo nucleus breakup, needs an accurate treatment of the transitions from bound to continuum states induced by the nuclear and Coulomb potentials. When the transition probability is not very small, a non-perturbative framework might be necessary. Nuclear excitation dominates at small impact parameters whereas the Coulomb potential being long range acts over a larger impact parameter interval. In this article, we propose an effective breakup amplitude which meets a number of requirements necessary for an accurate quantitative description of the breakup reaction mechanism. Furthermore our treatment gives some insight on the interplay between time dependent perturbation theory and sudden approximation and it allows to include the nuclear and Coulomb potentials to all orders within an eikonal-like framework.