The contribution of axial-vector mesons to hyperfine structure of muonic hydrogen

TL;DR

This paper calculates the impact of axial-vector meson exchange on the hyperfine structure of muonic hydrogen, revealing a significant contribution that influences the proton radius puzzle and experimental comparisons.

Contribution

It introduces a detailed calculation of axial-vector meson exchange effects on muonic hydrogen hyperfine splitting, highlighting their importance for resolving the proton radius puzzle.

Findings

Axial-vector meson exchange significantly affects hyperfine splitting.

The contribution is large enough to impact experimental data interpretation.

Discussion of implications for the proton radius puzzle.

Abstract

The contribution from the axial-vector meson exchange to the potential of the muon-proton interaction in muonic hydrogen induced by anomalous axial-vector meson coupling to two photon state is calculated. It is shown that such contribution to the hyperfine splitting in muonic hydrogen is large and important for a comparison with precise experimental data. In the light of our result, the proton radius "puzzle" is discussed.