Rotter, Ingrid Max Planck Institute for the Physics of Complex Systems, Max Planck Society;
https://link.springer.com/article/10.1140/epjd/e2018-90031-1 (Publisher version)
1703.04441.pdf (Preprint), 866KB
Eleuch, H., & Rotter, I. (2018). Critical points in two-channel quantum systems. European Physical Journal D, 72(8): 138. doi:10.1140/epjd/e2018-90031-1.