We propose a direct search for the X17 particle, which was conjectured to explain the ATOMKI 8Be and 4He anomalies, through the dilepton photoproduction process on a nucleon in the photon energy range below or around the pion production threshold. For the scenarios of either pseudoscalar, vector, or axial-vector quantum numbers of the conjectured X17, we use existing constraints to estimate the X17 signal process. For dilepton resolutions which have been achieved in previous experiments, a signal-to-background ratio of up to an order of magnitude is found for a neutron target, and in particular for the pseudoscalar and vector X17 scenarios.
Cite
@article{arxiv.2110.06055,
title = {X17 discovery potential in the $\gamma N \rightarrow e^+ e^- N$ process at electron scattering facilities},
author = {Johannes Backens and Marc Vanderhaeghen},
journal= {arXiv preprint arXiv:2110.06055},
year = {2022}
}