Probing quantum field theory particle mixing and dark-matter-like effects with Rydberg atoms A. Capolupo, S. M. Giampaolo, G. Lambiase and A. Quaranta Eur. Phys. J. C, 80 5 (2020) 423 Published online: 15 May 2020 DOI: 10.1140/epjc/s10052-020-7959-x