The Contribution of the Sigma-Meson to the Lamb Shift of Muonic Hydrogen

Abstract

The scalar meson exchange contribution to the potential of the muon-proton interaction in muonic hydrogen induced by the scalar meson coupling to two photon state is calculated. An estimate of transition form factor $$S \to \gamma \gamma $$ is given on the basis of quark model and experimental data on the decay widths $${{\Gamma }_{{S\gamma \gamma }}}.$$ It is shown that scalar meson exchange contribution to the Lamb shift in muonic hydrogen $$\Delta {{E}^{{Ls}}}(2P - 2S)$$ is large and important for a comparison with precise experimental data.