Spectral shape differences between photons produced in π0→γ+γ and π0→γ+AD may provide a new avenue for dark photon searches. Assuming 70 μm thick tungsten foils separated by 200 μm and a 1 GeV proton beam, we developed a GEANT4 model to estimate photon production and detection including background. Our results demonstrate that multiple campaign runs with a 10-50 μA beam could probe previously unexplored regions of parameter space in models where the dark photon has predominantly invisible decays. The results are highly model independent.
@article{arxiv.2605.13696,
title = {Dark photon searches in the photon channel},
author = {D. Aristizabal Sierra and A. Betancur and K. Pohl and J. Velez},
journal= {arXiv preprint arXiv:2605.13696},
year = {2026}
}