Connecting Collisional and Photofragmentation Resonances in the H$_2$ Ungerade Symmetry

TL;DR

This paper extends a theoretical framework to connect collisional and photofragmentation resonances in H₂ ungerade states, providing insights into their spectral features and experimental observability.

Contribution

The work develops an energy-dependent frame transformation theory for ungerade H₂ states, including rotational effects, and benchmarks it against models and experiments.

Findings

Resonances appear in different observables with varied line shapes

The theory accurately reproduces spectral features of H₂ ungerade states

Connections between dissociative recombination and photoabsorption are clarified

Abstract

A recently developed energy-dependent frame transformation theory that incorporates both ionization and dissociation channels of the H$_2$ molecule, is extended to treat the ungerade states that occur both in dissociative recombination and as the final state in ground state photoabsorption. The theoretical treatment includes the rotational degrees of freedom and is benchmarked against a two-dimensional model that can be solved with high accuracy and also compared with photoabsorption experiments. Analysis of the resulting spectra shows how the same resonances appear in very different observables, often with quite different line shapes.