BBR-induced Stark shifts and level broadening in a helium atom

Abstract

The precise calculations of blackbody radiation (BBR)-induced Stark shifts and depopulation rates for lowlying 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.

Lowest-Order Thermal Correction to the Hydrogen Recombination Cross-Section in Presence of Blackbody Radiation

“…Recently, the influence of finite lifetimes on the stimulated transition rates in hydrogen and helium atoms was studied in [16][17][18], while this effect for bound-free transitions is described in detail in [1]. In the latter case, the numerical calculations become much more complicated when summing over nl for the recombination/ionization coefficients due to the presence of the Lorentz factor.…”

Lowest order thermal correction to the hydrogen recombination cross section in presence of blackbody radiation

“…Recently the influence of finite lifetimes on the stimulated transition rates in hydrogen and helium atoms has been studied in [16][17][18], while this effect for bound-free transitions is described in detail in [1]. In the latter case, the numerical calculations become much more complicated when summing over nl for the recombination/ionization coefficients due to the presence of the Lorentz factor.…”

Thermal corrections to the bound-electron $g$-factor

“…In our recent works, bound-state quantum electrodynamics theory at finite temperature (BS-TQED) has been developed to calculate thermal effects in atomic systems [37][38][39][40]. Within the framework of this theory and Line Profile Approach (LPA) [41], various corrections to the transition probabilities and ionization/recombination cross-sections were also calculated [37,[42][43][44][45]. In this work, using previously developed methods for calculating finite temperature effects, we study thermal one-loop radiative corrections to the g-factor of a bound electron in the presence of BBR.…”