Forward doubly-virtual Compton scattering off an unpolarized deuteron in pionless effective field theory

We calculate the forward unpolarized doubly-virtual Compton scattering (VVCS) off the deuteron in the framework of pionless effective field theory, up to next-to-next-to-next-to-leading order (N3LO) for the longitudinal and next-to-leading order for the transverse amplitude. The charge elastic form factor of the deuteron, obtained from the residue of the longitudinal VVCS amplitude, is used to extract the value of the single unknown two-nucleon one-photon contact coupling that enters the longitudinal amplitude at N3LO. We also study the lowest spin-independent generalized polarizabilities of the deuteron. The calculated unpolarized VVCS amplitude provides a high-precision model-independent input for a future calculation of the two-photon-exchange correction to the Lamb shift of muonic deuterium.

Automated summary

The study calculates the forward unpolarized doubly-virtual Compton scattering off the deuteron within the framework of pionless effective field theory, providing important insights for future experiments related to the extracted physical quantities. The results of the study also offer a high-precision model-independent input for the calculation of the two-photon-exchange correction to the Lamb shift of muonic deuterium.