BBR-induced Stark shifts and level broadening in helium atom

TL;DR

This paper presents precise calculations of blackbody radiation-induced Stark shifts and level broadening in helium, highlighting the impact of Stark-mixing on state lifetimes and implications for cosmic microwave background formation.

Contribution

It introduces a variational approach to accurately compute BBR-induced effects on helium's energy levels and decay rates, including Stark-mixing phenomena.

Findings

BBR causes significant Stark shifts and level broadening in helium.

Stark-mixing notably reduces lifetimes of helium's excited states.

Implications for cosmic microwave background formation are discussed.

Abstract

The precise calculations of blackbody radiation (BBR)-induced Stark shifts and depopulation rates for low-lying states of helium atom with the use of variational approach are presented. An effect of the BBR-induced induced Stark-mixing of energy levels is considered. It is shown that this effect leads to a significant reduction of lifetimes of helium excited states. As a consequence the influence of Stark-mixing effect on the decay rates of metastable states in helium is discussed in context of formation processes of the cosmic microwave background.