To describe fusion, coupled channels models typically implement an absorbing potential or incoming wave boundary condition to capture incoming flux that penetrates the fusion barrier. These flux-trapping conditions obscure the dissipative processes that lead to fusion, preventing any understanding of how the apparently irreversible thermalisation of the compound nucleus can occur within an isolated quantum many-body system. Here, we approach modelling fusion with a time-dependent coupled channels model that does not require these conditions. Instead, incoming flux is trapped by allowing the wavefunction to couple to a large number of channels once inside the barrier. Results suggest that with sufficiently many channels included in the system, the transmission of the wavefunction through the potential barrier could be accurately reproduced without artificial flux-trapping conditions.
Webber et al. (Wed,) studied this question.