Determination of the ${\Lambda }_{c}^{+}$ spin via the reaction ${e}^{+}{e}^{-}\to {\Lambda }_{c}{\overline{\Lambda }}_{c}$

We report on a comparison of two possible ${\Lambda }_{c}^{+}$ spin hypotheses, $J=\frac{1}{2}$ and $\frac{3}{2}$, via the process ${e}^{+}{e}^{-}\to {\Lambda }_{c}^{+}{\overline{\Lambda }}_{c}^{-}$, using the angular distributions of ${\Lambda }_{c}^{+}$ decays into $p{K}_{S}^{0}$, $\Lambda {\pi }^{+}$, ${\Sigma }^{0}{\pi }^{+}$, and ${\Sigma }^{+}{\pi }^{0}$. The data were recorded at $\sqrt{s}=4.6\text{}\text{}\mathrm{GeV}$ with the BESIII detector and correspond to an integrated luminosity of $587\text{}\text{}{\mathrm{pb}}^{-1}$. The ${\Lambda }_{c}^{+}$ spin is determined to be $J=\frac{1}{2}$, with this value favored over the $\frac{3}{2}$ hypothesis with a significance corresponding to more than 6 Gaussian standard deviations.