Lepton universality and lepton flavor conservation tests with dineutrino modes Rigo Bause, Hector Gisbert, Marcel Golz and Gudrun Hiller Eur. Phys. J. C, 82 2 (2022) 164 Published online: 22 February 2022 DOI: 10.1140/epjc/s10052-022-10113-6