Simplified Fixed-Point Perturbation Theory and Its Application to the Coulomb + Short-Range Potential

摘要

The radial Schroedinger equation and its bound-state solutions for the interaction V(r)=Vsub(Coulomb) + Vsub(Pade), where Vsub(Pade)(r)=(b + cr)/(1 + drsup(2)) are considered. In order to construct exactly the Feshbach effective Hamiltonian Hsup(eff), the fixed-point-substraction technique is employed and its simplification is proposed. The first two terms in the resulting asymptotic expansions of PSIsub(n) and Hsup(eff) are calculated and interpreted as a new type of perturbation theory. 13 refs, submitted to the journal J. Phys. (Atomindex citation 18:006539)