New limits on dinucleon decay into invisible channels

Abstract

Data of the radiochemical experiment (E.L. Fireman, 1978) with 1.7 t of KC2H3O2, accumulated deep underground during ≃ 1 yr, were reanalyzed to set limits on dinucleon (nn and np) decays into invisible channels (disappearance, decay into neutrinos, etc.). The obtained lifetime bounds τ np τ; 2.1×1025 yr and τ nn τ;4.2×1025 yr (at 90% C.L.) are better (or competitive) than those established in the recent experiments.