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/ is included. We observe clear pJ/ψ production in Υ (1, 2 S) decays and measure the branching fractions to be B (1S) pJ/ +anything=8. 1 0. 6 (stat. ) 0. 5 (syst. ) 10^-5 and B (2S) pJ/ +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 (1, 2S) P₂^++anything B (P₂^+ pJ/) to be at the 10 − 6 level.