Helium energy levels including $m{\alpha }^6$ corrections

Abstract

The $m{\alpha }^6$ correction to energy is expressed in terms of an effective Hamiltonian $H^{(6)}$ for an arbitrary state of helium. Numerical calculations are performed for $n=2$ levels, and the previous result for the $2^{3}P$ centroid is corrected. While the resulting theoretical predictions for the ionization energy are in moderate agreement with experimental values for $2^3{S}_1$, $2^{3}P$, and $2^1{S}_0$ states, they are in significant disagreement for the singlet state $2^1{P}_1$.

11 pages, with erratum submitted to Phys. Rev. A (2007)

References in corpus (3)

• ${\alpha }^4$ Ry corrections to singlet states of helium
• Improved theory of helium fine structure
• Helium 2 3S - 2 1S metrology at 1557 nm

Cited by in corpus (3)

• Relativistic, QED, and finite nuclear mass corrections for low-lying states of Li and Be${}^{+}$
• Prospects for precision measurements of atomic helium using direct frequency comb spectroscopy
• Fine and hyperfine splitting of the 2P state in Li and Be${}^{+}$