Resonant states and pseudospin symmetry in the Dirac Morse potential

TL;DR

This paper applies the complex scaling method to analyze resonances and pseudospin symmetry in a Dirac particle within a Morse potential, revealing strong pseudospin symmetry and sensitivity to potential parameters.

Contribution

It demonstrates the application of the complex scaling method to the Dirac Morse potential and explores the relationship between pseudospin symmetry and potential shape.

Findings

Excellent agreement with nonrelativistic results in the nonrelativistic limit

Discovery of well pseudospin symmetry in the model

Resonant parameters are highly sensitive to potential shape

Abstract

The complex scaling method is applied to study the resonances of a Dirac particle in a Morse potential. The applicability of the method is demonstrated with the results compared with the available data. It is shown that the present calculations in the nonrelativistic limit are in excellent agreement with the nonrelativistic calculations. Further, the dependence of the resonant parameters on the shape of the potential is checked, and the unusual sensitivity to the potential parameters is revealed. By comparing the energies and widths of the pseudospin doublets, well pseudospin symmetry is discovered in the present model. The relationship between the pseudospin symmetry and the shape of the potential is investigated by changing the Morse potential shaped by the dissociation energy, the equilibrium intermolecular distance, and the positive number controlling the decay length of the potential.