Quantum coherence and decoherence in low energy nuclear collisions: from superposition to irreversibility

The successful coupled-channels model of peripheral reactions has been widely used to model fusion. Following measurements of inhibition of fusion at deep sub-barrier energies, it has been proposed that to properly describe the nuclear fusion process, quantum decoherence and energy dissipation should be treated simultaneously with coherent quantum superpositions, the latter being the basis of the coupled-channels model. The necessity for a simultaneous inclusion of quantum coherence and decoherence is discussed, and the first implementation through a density matrix model is described.