On the measurement of surface oscillations using a femtosecond laser

Effect of Electron Correlation and Breit Interaction on Energies, Oscillator Strengths, and Transition Rates for Low-Lying States of Helium

“…In addition, our result 8.1268 × 10 −8 s −1 is in better agreement with the experimental result 9.1 × 10 −8 s −1 (Ref. [8]) than the theoretical results 15.1 × 10 −8 s −1 of Lin et al [35] and 6.1 × 10 −8 s −1 of Baklanov et al [5] for 2 3 𝑆 1 -1 1 𝑆 0 M1 transition. Similar to the M1 transition of 1𝑠2𝑝( 3 𝑃 0,1,2 and 1 𝑃 1 ) states, the Breit interaction also plays an important role in E2 transitions.…”

“…For the 2 3 𝑆 1 -2 1 𝑆 0 M1 transition, our result 8.1268 × 10 −8 s −1 is better in agreement with the experimental result 9.1 × 10 −8 s −1 (Ref. [8] ) than the theoretical results 15.1 × 10 −8 s −1 of Lin et al [35] and 6.1 × 10 −8 s −1 of Baklanov et al [5] The result of Baklanov et al [5] differs from the results of experiment, [8] because the correlated nonrelativistic wave functions were used.…”

“…Until 2011, Rooij et al obtained the transition rate as 9.1 × 10 −8 s −1 using the 1557 nm laser to directly measure the forbidden transition 2 1 𝑆 0 -2 3 𝑆 1 of He I. [8] The experimental result is different from the earlier theoretical results, [5,35] which arouses the interest to further calculate the transition rate.…”

“…[35] However, Baklanov and Denisov calculated this forbidden transition rate as 6.11 × 10 −8 s −1 (Ref. [5]) in 1997 by using the correlated nonrelativistic wave functions discussed the detail in Ref. [37].…”