Lamb shift in muonic deuterium Available to Purchase

We consider the two-photon exchange contribution to the 2P-2S Lamb shift in muonic deuterium in the framework of forward dispersion relations. The dispersion integrals are evaluated with minimal model dependence using experimental data on elastic deuteron form factors and inelastic electron-deuteron scattering, both in the quasielastic and hadronic range. The subtraction constant that is required to ensure convergence of the dispersion relation for the forward Compton amplitude T₁ (ν,Q²) is related to the deuteron magnetic polarizability β(Q²) and represents the main source of uncertainty in our analysis. We obtain for the Lamb shift ΔE_2P-2S = 1.620±0.190 meV and discuss ways to further reduce this uncertainty.