Using data samples of 102 million $\mathrm{\Upsilon }(1S)$ events and 158 million $\mathrm{\Upsilon }(2S)$ events collected by the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider, we search for $[udsc\overline{c}]$ pentaquark states decaying to $J/\psi \mathrm{\Lambda }$. Using the first observations of $\mathrm{\Upsilon }(1S,2S)$ inclusive decays to $J/\psi \mathrm{\Lambda }$, we find evidence of the $P_{c\overline{c}s}(4459{)}^0$ state with a local significance of 3.3 standard deviations, including statistical and systematic uncertainties. We measure the mass and width of the $P_{c\overline{c}s}(4459{)}^0$ to be $(4471.7\pm 4.8\pm 0.6)\mathrm{MeV}/c^2$ and $(22\pm 13\pm 3)\mathrm{MeV}$, respectively. The branching fractions for $P_{c\overline{c}s}(4459{)}^0$ production are measured to be $\mathcal{B}[\mathrm{\Upsilon }(1S)\to P_{c\overline{c}s}(4459{)}^0/{\overline{P}}_{c\overline{c}s}(4459{)}^0+\mathrm{anything}]=(3.5\pm 2.0\pm 0.2)\times {10}^{-6}$ and $\mathcal{B}[\mathrm{\Upsilon }(2S)\to P_{c\overline{c}s}(4459{)}^0/{\overline{P}}_{c\overline{c}s}(4459{)}^0+\mathrm{anything}]=(2.9\pm 1.7\pm 0.4)\times {10}^{-6}$. The inclusive branching fractions of $\mathrm{\Upsilon }(1S,2S)\to J/\psi \mathrm{\Lambda }/\overline{\mathrm{\Lambda }}$ are measured to be $\mathcal{B}[\mathrm{\Upsilon }(1S)\to J/\psi \mathrm{\Lambda }/\overline{\mathrm{\Lambda }}+\mathrm{anything}]=(36.9\pm 5.3\pm 2.4)\times {10}^{-6}$ and $\mathcal{B}[\mathrm{\Upsilon }(2S)\to J/\psi \mathrm{\Lambda }/\overline{\mathrm{\Lambda }}+\mathrm{anything}]=(22.3\pm 5.7\pm 3.1)\times {10}^{-6}$. We measure the visible cross section $\sigma (e^{+}{e}^{-}\to J/\psi \mathrm{\Lambda }/\overline{\mathrm{\Lambda }}+\mathrm{anything})=(90\pm 14\pm 6)\mathrm{fb}$ for the continuum production at $\sqrt{s}=10.52\mathrm{GeV}$. In all cases, the first uncertainties are statistical and the second are systematic.

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• Branching fraction
• Hadron production
• Hadronic decays
• Multiquark bound states
• Quark model