Proton structure corrections to electronic and muonic hydrogen hyperfine splitting

TL;DR

This paper provides a precise calculation of proton structure effects on hydrogen and muonic hydrogen hyperfine splitting, improving theoretical accuracy and comparing with experimental data.

Contribution

It offers the most recent proton structure dependent corrections to hyperfine splitting, integrating new experimental data for enhanced precision.

Findings

Calculated hyperfine splitting with under 1 ppm uncertainty

Results are about 1 standard deviation from experimental measurements

Ensured consistency between recoil and polarizability contributions

Abstract

We present a precise determination of the polarizability and other proton structure dependent contributions to the hydrogen hyperfine splitting, based heavily on the most recent published data on proton spin dependent structure functions from the EG1 experiment at the Jefferson Laboratory. As a result, the total calculated hyperfine splitting now has a standard deviation slightly under 1 part-per-million, and is about 1 standard deviation away from the measured value. We also present results for muonic hydrogen hyperfine splitting, taking care to ensure the compatibility of the recoil and polarizability terms.