Two-particle states in dense hydrogen plasmas with external electric fields

Atomic bound state energies are drastically changed by many-particle effects such as dynamical self-energy, dynamical screening and Pauli blocking (phase space occupation). The continuum edge is changed, too, so that the effective ionization energy may tend to zero with increasing density and bound states do not exist (Mott effect). Another possibility to influence the energy spectrum is the application of external electrical fields (Strak effect). Both the many-particle effects and the external field lead to a level broadening, i.e., to finite lifetimes of the two-particle states. In this paper, an effective Schrödinger equation is solved which takes into account both influences on the two-particle spectrum and wave functions. Real and imaginary parts of the spectrum are determined using the complex scaling method. The interrelation between external fields and many-particle effects in investigated. The work is of interest for kinetic properties of plasmas with ionization and recombination processes, where there is a competition of the influences mentioned.