Adiabatic description of resonant states in e^--H scattering by the method of extrapolation in the coupling constant

Abstract

The analytical properties of the scattering matrix in the adiabatic formulation of the multichannel scattering problem in a three-body system are investigated as functions of the coupling constant and energy in the framework of the adiabatic hyperspherical approach. The localization and the character of pole motion in the complex coupling constant plane and a n the Riemann energy surface are studied. On this basis a method for obtaining the resonant state parameters by extrapolation in the coupling constant using Pad6 approrimants of the second type is suggested. The developed approach is applied to calculate the position and width of the 'P" shape resonance in the e--H scattering. The position E.=0.015 eV and width r,=0.012eV of the H-'P" shape resonance calculated in the simple one-channel diabatic approximation are in good agreement with other theoretical calculations.