Double Electron Capture in H^{+}+H^{-} Collisions.

Area of Science:

• Atomic and Molecular Physics
• Quantum Mechanics
• Collision Physics

Background:

• The double electron capture process in H+ + H- collisions is a fundamental yet challenging problem in atomic physics.
• Previous theoretical calculations have failed to accurately reproduce experimental total cross sections for this system.
• Observed oscillations in experimental data were previously attributed to quantum interferences between ionic states.

Purpose of the Study:

• To investigate the double electron capture process in H+ + H- collisions.
• To accurately calculate absolute cross sections for this collision system.
• To elucidate the origin of oscillations in the experimental cross sections.

Main Methods:

• Employed a fully correlated two-active-electron semiclassical atomic-orbital close-coupling approach.
• Calculated absolute cross sections for collision energies ranging from 60 eV to 20 keV.
• Utilized a Rosenthal-like model based on molecular treatment to support interpretations.

Main Results:

• The developed method successfully reproduces experimental total cross sections in both magnitude and shape.
• Demonstrated that oscillations arise from coherence effects between double electron capture and transfer-excitation processes.
• Provided an alternative interpretation for the observed oscillatory behavior.

Conclusions:

• The study presents a successful theoretical model for the H+ + H- double electron capture process.
• The findings offer a new perspective on the underlying physics governing collision dynamics.
• This work resolves a long-standing challenge in atomic collision physics.