Proton Structure Corrections to Hydrogen Hyperfine Splitting

Abstract

The largest uncertainty in calculations of hydrogen ground-state hyperfine splitting comes from corrections due to proton stucture. We review these corrections, with special mention of the inelastic, or polarizability, corrections which have been recently re-evaluated. Summing up the arguably best current values for the calculated corrections leaves us 1-2 ppm short of the experimental data. We speculate how one may explain this shortfall, and along the way broadly outline the derivations of the relevant formulas, attempting to explain how certain terms come to appear and commenting on the use of unsubtracted dispersion relations.

A review based on material discussed at the conference series "Precision Physics of Simple Atomic Systems" (2006, Venice, Italy, 12-17 June), 15 pages, 4 figures

References in corpus (17)

• Precision physics of simple atoms: QED tests, nuclear structure and fundamental constants
• Two-photon exchange and elastic electron-proton scattering
• Measurements of the $Q^2$-Dependence of the Proton and Neutron Spin Structure Functions g1p and g1n
• On the rms-radius of the proton
• Dispersion relations in real and virtual Compton scattering
• Partonic calculation of the two-photon exchange contribution to elastic electron-proton scattering at large momentum transfer
• Precision Measurement of the Proton and Deuteron Spin Structure Functions g2 and Asymmetries A2
• Measurement of the Proton Spin Structure Function $g_1(x,Q^2)$ for $Q^2$ from 0.15 to 1.6 GeV${}^2$ with CLAS
• Extraction of two-photon contributions to the proton form factors
• 2S Hyperfine splitting of muonic hydrogen
• Leading and higher twists in the proton polarized structure function at large Bjorken x
• Proton polarizability contribution to the hyperfine splitting in muonic hydrogen
• The Drell-Hearn Sum Rule at Order Alpha**3
• New experimental constraints on polarizability corrections to hydrogen hyperfine structure
• Comment on "Constraints on proton structure from precision atomic physics measurements"
• Proton polarizability effect in the hyperfine splitting of the hydrogen atom
• Jefferson Lab's results on the Q^2-evolution of moments of spin structure functions