Line Profile Asymmetry in Precision Spectroscopy

TL;DR

This review analyzes line profile asymmetry in high-precision hydrogen and helium spectroscopy using a rigorous QED framework, highlighting quantum interference, nonresonant effects, and astrophysical implications.

Contribution

It provides a comprehensive QED-based derivation of nonresonant line profile extensions, addressing gaps in existing literature and analyzing angular correlations in quantum interference.

Findings

QED derivation of nonresonant Lorentz profile extension

Analysis of angular correlations in quantum interference

Implications for astrophysical spectroscopy

Abstract

In this review, we have investigated the asymmetry of the line profile in precision one- and two-photon spectroscopy of hydrogen and helium atoms within the framework of a rigorous QED approach. A detailed analysis of the angular correlations of the quantum interference effect has been carried out using various examples. Nonresonant effects are also considered in relation to some astrophysical problems. In particular, a rigorous QED derivation of the nonresonant extension for the Lorentz line profile is given using the Ly$_{\alpha}$ transition as an example; such a QED derivation has been lacking in the literature.