Evidence of a structure in ${\bar{K}}^0{\mathrm{\Lambda }}_c^{+}$ consistent with a charged ${\mathrm{\Xi }}_c(2930{)}^{+}$, and updated measurement of ${\bar{B}}^0\to {\bar{K}}^0{\mathrm{\Lambda }}_c^{+}{\bar{\mathrm{\Lambda }}}_c^{-}$ at Belle

We report evidence for the charged charmed-strange baryon ${\mathrm{\Xi }}_c(2930{)}^{+}$ with a signal significance of 3.9$\sigma$ with systematic errors included. The charged ${\mathrm{\Xi }}_c(2930{)}^{+}$ is found in its decay to $K_S^0{\mathrm{\Lambda }}_c^{+}$ in the substructure of $\bar{B}^{0} \to K^{0}{S} \Lambda{c}^{+} \bar{\Lambda}{c}^{-}$decays\mathrm{.}Themeasuredmassandwidthare$[2942.3 \pm 4.4 (\rm stat.) \pm 1.5(\rm syst.)]$MeV\mathrm{/}$c^{2}$and$[14.8 \pm 8.8(\rm stat.) \pm 2.5(\rm syst.)]$MeV,respectively,andtheproductbranchingfractionis$\cal{B}(\bar{B}^{0} \to \Xi_c(2930)^{+} \bar{\Lambda}{c}^{-}) \cal{B}(\Xi_c(2930)^{+}\to \bar{K}^{0} \Lambda_{c}^{+})=[2.37 \pm 0.51 (\rm stat.)\pm 0.31(\rm syst.)]\times 10^{-4}$\mathrm{.}Wealsomeasure$\cal{B}(\bar{B}^{0} \to \bar{K}^{0} \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-}) = [3.99 \pm 0.76(\rm stat.) \pm 0.51(\rm syst.)] \times 10^{-4}$ with greater precision than previous experiments, and present the results of a search for the charmonium-like state $Y(4660)$ and its spin partner, $Y_{\eta }$, in the ${\mathrm{\Lambda }}_c^{+}{\bar{\mathrm{\Lambda }}}_c^{-}$ invariant mass spectrum. No clear signals of the $Y(4660)$ or $Y_{\eta }$ are observed and the 90% credibility level (C.L.) upper limits on their production rates are determined. These measurements are obtained from a sample of $(772\pm 11)\times {10}^{6}B\bar{B}$ pairs collected at the $\mathrm{{\rm Y}}(4S)$ resonance by the Belle detector at the KEKB asymmetric energy electron-positron collider.