Rediscovery of $B^0\to J\mathrm{/}\psi K_L^0$ at Belle II

We present preliminary results on the reconstruction of the $B^0\to J\mskip 1mu / \psi\mskip 2mu K^0_{\scriptscriptstyle L}$decay,where$J\mskip 1mu / \psi\mskip 2mu\to\mu^+\mu^-$or$e^+e^-$. Using a dataset corresponding to a luminosity of $62.8\pm 0.6f{b}^{-1}$ collected by the Belle II experiment at the SuperKEKB asymmetric energy $e^{+}{e}^{-}$ collider, we measure a total of $267\pm 21$ candidates with $J\mathrm{/}\psi \to {\mu }^{+}{\mu }^{-}$ and $226\pm 20$ with with $J\mathrm{/}\psi \to e^{+}{e}^{-}$. The quoted errors are statistical only.