Photodetachment near a repulsive center

TL;DR

This paper derives an analytical formula for the total photodetachment cross section of H$^-$ near a repulsive center, extending closed-orbit theory below the zero-field threshold and validating it against quantum calculations.

Contribution

It introduces an extended analytical approach for photodetachment near a repulsive center, applicable below the zero-field threshold, and compares it with quantum results and electric field cases.

Findings

Analytical formula matches quantum calculations accurately.

Photodetachment behavior near a repulsive center differs from that in a homogeneous electric field.

Extension of closed-orbit theory to sub-threshold energies.

Abstract

We study the total photodetachment cross section of H$^-$ near a repulsive center. An analytical formula for the photodetachment cross section is obtained using the standard closed-orbit theory and extending it to the energy range below the zero-field threshold. The formula is found to be accurate by comparing with an exact quantum calculation. A comparison with the photodetachment cross section in an effective homogeneous electric field is made, and we discuss the similarities and differences of the two systems.