Target-normal single-spin asymmetry in elastic electron-nucleon scattering
Abstract
We estimate the target-normal single-spin asymmetry at nearly forward angles in elastic electron-nucleon scattering. In the leading-order approximation, this asymmetry is proportional to the imaginary part of the two-photon exchange (TPE) amplitude, which can be expressed as an integral over the doubly virtual Compton scattering (VVCS) tensor. We develop a model that parametrizes the VVCS tensor for the case of nearly forward scattering angles. Our parametrization ensures a proper normalization of the imaginary part of the TPE amplitude on the well-known forward limit expression, which is given in terms of nucleon structure functions measurable in inelastic electron-nucleon scattering experiments. We discuss applicability limits of our theory and provide target-normal single-spin asymmetry predictions for both elastic electron-proton and electron-neutron scattering.
Cite
@article{arxiv.1803.04004,
title = {Target-normal single-spin asymmetry in elastic electron-nucleon scattering},
author = {Oleksandr Koshchii and Andrei Afanasev},
journal= {arXiv preprint arXiv:1803.04004},
year = {2018}
}
Comments
14 pages, 6 figures; v2: contains extended discussions, results are unchanged; v3: minor changes, matches published version; v4: corrected Fig. 5