Neutral Decays of the J/$\psi$ Particle

Physics letters / B 66(5), 489 - 492 (1977). doi:10.1016/0370-2693(77)90594-9
The decay of J/ψ (3.1) into final states containing no charged particles has been studied experimentally. The partial decay width for the observed neutral decays is (470 ± 160) eV. The decay modes J/ ψ → γη → 3 γ and J/ ψ γη ′ → 3 γ are identified and the branching ratios J ψ → γη J ψ → all = (1.3 ±0.4) × 10 −3 , and J ψ → γη′ J ψ → γη = 1.8 ±0.8 , are derived. Upper limits for the decay modes J/ ψ → γπ 0 and J/ ψ → γγ are given.
Published by North-Holland Publ., Amsterdam