SEMICLASSICAL PERTURBATION APPROACH TO QUANTUM REFLECTION

We consider the problem of quantum ''reflection above the barrier,'' i ntroducing a distorted-wave Born approximation based on the primitive semiclassical Wentzel-Kramers-Brillouin wave function. The idea genera lizes to the concept of an unperturbed Hamiltonian defined as the exac t Hamiltonian plus small parts which ''turn off'' nonclassical process es such as barrier reflection and barrier tunneling.