Orientation-dependent stopping power of a degenerate electron gas for slow homonuclear dimers

We present a theoretical study on the orientation-dependent retarding force experienced by slow homonuclear dimers moving at arbitrary alignment with the direction of their flight in a three-dimensional degenerate electron gas of metallic densities. The analytical results are derived within the approximate framework of Brueckner for elastic scattering of an electron by a system of two auxiliary potentials of short range. The influence of the screened field of a single constituent of the slowly moving composite projectile on the scattering electron is modeled by an effective phase shift parameter. in the short-range potential in order to characterize the real-constituent system coupling due to displacement. The orientation-dependent closed expressions reveal the dependence of observables on the classical geometry and quantum dynamics. The interplay of wave-interference and multiple scattering in the orientation-dependent friction is analyzed for realistic sets of the input parameters. Comparison with experimental data is made and good agreement is found.