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

Abstract Using the data samples of 102 million Υ(1S) and 158 million Υ(2S) events collected by the Belle detector, we search for a pentaquark state in the pJ/ψ final state from Υ(1, 2S) inclusive decays. Here, the charge-conjugate $$\overline{p }J/\psi $$ is included. We observe clear pJ/ψ production in Υ(1, 2S) decays and measure the branching fractions to be $$\mathcal{B}[\Upsilon (1S)\to pJ/\psi +anything]=[8.1\pm 0.6(stat.)\pm 0.5(syst.)]\times {10}^{-5}$$ and $$\mathcal{B}[\Upsilon (2S)\to pJ/\psi +anything]=[4.3\pm 0.5(stat.)\pm 0.4(syst.)]\times {10}^{-5}$$ . 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 $$\sqrt{s}=10.52$$ 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, 2S) inclusive decays. We determine the upper limits of $$\mathcal{B}\left[\Upsilon \left({1},{2}S\right)\to {P}_{c}^{+}+anything\right]\cdot \mathcal{B}\left({P}_{c}^{+}\to pJ/\psi \right)$$ to be at the 10 −6 level.