About universal scalings in double K-shell photoionization

TL;DR

This paper investigates the conditions and accuracy of universal scaling laws in double K-shell photoionization, analyzing physical mechanisms and comparing theoretical predictions with recent experimental data using QED perturbation theory.

Contribution

It provides a theoretical analysis of universal scalings in double K-shell photoionization and examines their validity and physical mechanisms involved.

Findings

Universal scalings are valid under specific conditions.

Different physical mechanisms may contribute to double ionization.

Theoretical results align with recent experimental measurements.

Abstract

We discuss the problem of the universal scalings in the double ionization of atomic K-shell electrons caused by absorption of a single photon. In particular, we envisage the following questions: Under which conditions and up to which accuracy the universal scalings are realized? Does it make sense to talk about different physical mechanisms in the double-ionization process? Finally, we present also the theoretical analysis of recent experimental measurements performed on neutral atoms. As a testing ground, QED perturbation theory is employed.