Helium fine structure theory for determination of α

Abstract

We present recent progress in the calculation of the helium fine-structure splitting of the 2^3P_J states, based on the quantum electrodynamic theory. Apart from the complete evaluation of mα^7 and m^2/Mα^6 corrections, we have performed extensive tests by comparison with all experimental results for light helium-like ions and with the known large nuclear charge asymptotics of individual corrections. Our theoretical predictions are still limited by the unknown mα^8 term, which is conservatively estimated to be 1.7 kHz. However, comparison with the latest experimental result for the 2^3P_0 - 2^3P_2 transition [M. Smiciklas and T. Shiner, Phys. Rev. Lett. 105, 123001 (2010)] suggests that the higher-order contribution is in fact much smaller than the theoretical estimate. This means that the spectroscopic determination of αcan be significantly improved if another measurement of the 2^3P_0 - 2^3P_2 transition in helium-like Li^+ or Be^{2+} ion is performed.

Proceedings of ICAP2010. A misprinted digit is corrected in Table 2

References in corpus (4)

• Revised value of the eighth-order electron g-2
• Fine structure of helium-like ions and determination of the fine structure constant
• A Determination of the Fine Structure Constant using Precision Measurements of Helium Fine Structure
• Improved theory of helium fine structure

Cited by in corpus (7)

• Testing fundamental interactions on the helium atom
• Complete ${\alpha }^{7}m$ Lamb shift of helium triplet states
• Higher-order recoil corrections for triplet states of the helium atom
• Ultrahigh-precision measurement of the $n=2$ triplet P fine structure of atomic helium using frequency-offset separated oscillatory fields
• Atomic structure calculations of helium with correlated exponential functions
• Quantum electrodynamic corrections to the $1s3d$ states of the helium atom
• Frequency measurements of transitions from the $2^3{P}_2$ state to the $5^1{D}_2$, $5^3{S}_1$, and $5^{3}D$ states in ultracold helium