Scattering from a nonsymmetric potential in one dimension as a coupled-channel problem

We study the partial-wave description of scattering of a particle from a one-dimensional potential in quantum mechanics. There are two partial waves, with even and odd parity. They are decoupled if the potential V(x) is symmetric, i.e., V(x)=V(−x). If V(x)≠V(−x), however, the two partial waves are coupled. This coupled-channel problem can be handled in terms of two eigenphases and a mixing parameter. This method enables us to shed new light on the transmission and reflection probabilities at threshold.