# The contribution of pseudoscalar mesons to hyperfine structure of muonic hydrogen

## TL;DR

This paper calculates how pseudoscalar mesons influence the hyperfine structure of muonic hydrogen using quantum electrodynamics and experimental form factors, providing numerical estimates for S and P levels.

## Contribution

It introduces a novel calculation of pseudoscalar meson contributions to muonic hydrogen hyperfine structure using updated form factors and QCD asymptotics.

## Key findings

- Quantitative estimates of meson contributions to hyperfine splitting.
- Use of experimental data for transition form factors.
- Application of quasipotential method in QED.

## Abstract

In the framework of the quasipotential method in quantum electrodynamics we calculate the contribution of pseudoscalar mesons to the interaction operator of a muon and a proton in muonic hydrogen atom. The parametrization of the transition form factor of two photons into $\pi$, $\eta$ mesons, based on the experimental data on the transition form factors and QCD asymptotics is used. Numerical estimates of the contributions to the hyperfine structure of the spectrum of the S and P levels are presented.