Relativistic corrections to He I transition rates

摘要

Abstract: The relativistic corrections to the theoretical oscillator strengths of light elements such as helium are typicallynless than 0.1% and usually are ignored. However, they can be important for comparisons with the most accurate experi-nments, and they rapidly increase in magnitude with increasing nuclear charge. We have begun with the spin-forbiddennelectric-dipole transitions of neutral helium, using calculations consisting of (1) extremely accurate wave functions withoutnrelativistic corrections for both infinite and finite nuclear mass, (2) spin-changing matrix elements through the perturba-ntions of the wave functions by the spin-orbit and spin-other-orbit Breit operators, (3) the use of pseudostates in the sumsnover all the intermediate states including the continuum, and (4) the inclusion as perturbers of the 1S0 and 3S1 states thenpseudostates corresponding to the doubly excited npn’p 3P0nenand npn’p 1P1nenterms, respectively. As examples of these calcula-ntions, we present oscillator strengths for the transitions 1 1S0–2 3P1,2 1S0–2 3P1,2 3S1–2 1P1,2 1P1–3 3D1,2, and 2 3P1,2–3 1D2.