Search for a pentaquark state decaying into pJ/ψ in Υ(1, 2S) inclusive decays at Belle

A bstract Using the data samples of 102 million Υ(1 S ) and 158 million Υ(2 S ) events collected by the Belle detector, we search for a pentaquark state in the pJ/ψ final state from Υ(1 , 2 S ) inclusive decays. Here, the charge-conjugate p ̄J/ψ is included. We observe clear pJ/ψ production in Υ(1 , 2 S ) decays and measure the branching fractions to be B[Υ (1S)→ pJ/ψ +anything]=[8.1± 0.6(stat.)± 0.5(syst.)]× 10⁻⁵ and B[Υ (2S)→ pJ/ψ +anything]=[4.3± 0.5(stat.)± 0.4(syst.)]× 10⁻⁵ . We also measure the cross section of inclusive pJ/ψ production in e + e − annihilation to be σ ( e + e − → pJ/ψ + anything ) = [108 ± 11( stat. ) ± 6( syst. )] fb at √s=10.52 GeV using an 89 . 5 fb − 1 continuum data sample. There is no significant P c (4312) + , P c (4440) + or P c (4457) + signal found in the pJ/ψ final states in Υ(1 , 2 S ) inclusive decays. We determine the upper limits of B[Υ (1,2S)→ Pc⁺+anything]· B(Pc⁺→ pJ/ψ ) to be at the 10 − 6 level.