Observation of J/ψ → pp̅α₀(980) at BESII



Using 2.25 x 10⁸ J/ψ events collected with the BESIII detector at the BEPCII storage rings, we observe for the first time the process J/ψ → pp̅α₀(980), α₀ → π⁰η with a significance of 6.5σ (3.2σ including systematic uncertainties). The product branching fraction of J/ψ → pp̅α₀(980) → pp̅π⁰η is measured to be (6.8 ± 1.2 ± 1.3) x 10⁻⁵, where the first error is statistical and the second is systematic. This measurement provides information on the α₀ production near threshold coupling to pp̅ and improves the understanding of the dynamics of J/ψ decays to four-body processes.



Mesons, J/ψ particles (J/psi), Branching fractions, Alpha particles


Ministry of Science and Technology of China (no. 2009CB825200); National Natural Science Foundation of China (no. 11079008, 11179007, U1332201); National Natural Science Foundation of China (NSFC) (no. 10625524, 10821063, 10825524, 10835001, 10935007, 11125525, 11235011, 11335008, 11275189, 11322544, and 11375170); Chinese Academy of Sciences (CAS) Large-Scale Scientific Facility Program (no. KJCX2-YW-N29 and no. KJCX2-YW-N45); Ministry of Development of Turkey (no. DPT2006K-120470); National Natural Science Foundation of China (NSFC) (no. 11275189); U.S. Department of Energy (no. DE-FG02-04ER41291, DE-FG02-05ER41374, DE-FG02-94ER40823, and DESC0010118); National Research Foundation of Korea (no. R32-2008-000-10155-0).


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