Classical dynamics near the triple collision in two-electron atoms

Gregor Tanner, University of Nottingham

The quite unusual properties of spectra of two-electron atoms have puzzled atomic physicists for the last three decades. It became clear that spectra are best described in terms of approximate quantum numbers related to a collective electron-electron dynamics. The underlying classical (approximate) symmetries are, however, still largely uncovered. I am presenting here the first steps towards uncovering the ''hidden symmetries'' in two-electron atoms by investigate the classical motion in the full 5d phase space. The triple collision is a main source of chaos in such three body Coulomb problems. By employing the McGehee scaling technique, we analyse here for the first time in detail the three-body dynamics near the triple collision in 3 degrees of freedom. We reveal surprisingly simple dynamical patterns in large parts of the chaotic phase space. The underlying degree of order in the form of approximate Markov partitions may help in understanding the global structures observed in quantum spectra of two-electron atoms.