Higher-order recoil corrections for triplet states of the helium atom
arXiv:1610.04060 · doi:10.1103/PhysRevA.94.052508
Abstract
Nuclear recoil corrections of order $α^6\,m^2/M$ are calculated for the lowest-lying triplet states of the helium atom. It improves the theoretical prediction for the isotope shift of the $2^3S-2^3P$ transition energy and influences the determination of the ${}^3\textrm{He}-{}^4\textrm{He}$ nuclear charge radii difference. This calculation is a step forward on the way towards the direct determination of the charge radius of the helium nucleus from spectroscopic measurements.
45 pages