6533b7d6fe1ef96bd1266f77

RESEARCH PRODUCT

Soft-photon radiative corrections to the e−p→e−pl−l+ process

subject

description

We calculate the leading-order QED radiative corrections to the process ${e}^{\ensuremath{-}}p\ensuremath{\rightarrow}{e}^{\ensuremath{-}}p{l}^{\ensuremath{-}}{l}^{+}$ in the soft-photon approximation, in two different energy regimes which are of relevance to extract nucleon structure information. In the low-energy region, this process is studied to better constrain the hadronic corrections to precision muonic hydrogen spectroscopy. In the high-energy region, the beam-spin asymmetry for double-virtual Compton scattering allows us to directly access the generalized parton distributions. We find that the soft-photon radiative corrections have a large impact on the cross sections and are therefore of paramount importance to extract the nucleon structure information from this process. For the forward-backward asymmetry, the radiative corrections are found to affect the asymmetry only around or below the 1% level, whereas the beam-spin asymmetry is not affected at all in the soft-photon approximation, which makes them gold-plated observables to extract nucleon structure information in both the low- and high-energy regimes.