# Signatures of the orbital angular momentum of an infrared light beam in the two-photon transition matrix element: A step toward attosecond chronoscopy of photoionization

## TL;DR

This paper develops a theoretical framework for time-resolved photoionization using vortex beams with orbital angular momentum, revealing how this property influences electron dynamics during ionization in pump-probe experiments.

## Contribution

It introduces a novel theory linking vortex beam orbital angular momentum to electron dynamics in photoionization, advancing attosecond chronoscopy techniques.

## Key findings

- Orbital angular momentum affects electron dynamics independently of initial and final states.
- The theory enables new insights into ultrafast photoionization processes.
- Potential applications in attosecond chronoscopy of photoionization.

## Abstract

We present a theory of time-resolved photoionisation in the presence of a vortex beam. In a pump-probe setup, an extreme ultraviolet or an x-ray pump pulse triggers ionization, which is probed by a synchronized infrared pulse with non-zero orbital angular momentum. We show, how this property of the probe pulse affects the electron dynamics upon ionization, in a way that is independent of the initial and final angular momentum states of the ionizing system.