Fano interference and cross-section fluctuations in molecular photodissociation

TL;DR

This paper derives a comprehensive model for molecular photodissociation cross sections, incorporating both direct and indirect processes, and analyzes their statistical properties using random matrix theory, revealing unique signatures of direct processes.

Contribution

It introduces a unified expression for the total photodissociation cross section that includes both direct and indirect pathways, and characterizes their statistical behavior with random matrix theory.

Findings

Cross section exhibits generalized Beutler-Fano line shapes.

Direct processes significantly influence the statistical distribution of cross sections.

A unique signature of direct processes is identified in the cross-section distribution.

Abstract

We derive an expression for the total photodissociation cross section of a molecule incorporating both indirect processes that proceed through excited resonances, and direct processes. We show that this cross section exhibits generalized Beutler-Fano line shapes in the limit of isolated resonances. Assuming that the closed system can be modeled by random matrix theory, we derive the statistical properties of the photodissociation cross section and find that they are significantly affected by the direct processes. We identify a unique signature of the direct processes in the cross-section distribution in the limit of isolated resonances.