Observation of a New Excited $\mathrm{\Sigma }$ State in $\psi (3686)\to \bar{p}{K}^{+}{\mathrm{\Sigma }}^0+c\mathrm{.}c\mathrm{.}$

Using a data sample of $(2712.4\pm 14.3)\times {10}^6\psi (3686)$ events collected with the BESIII detector, a partial-wave analysis of $\psi (3686)\to \bar{p}{K}^{+}{\mathrm{\Sigma }}^0+c\mathrm{.}c\mathrm{.}$ is performed. A new excited $\mathrm{\Sigma }$ baryon state is observed with a statistical significance of $11.9\sigma$, and the mass and width are measured as $(2334.7\pm 7.9\pm 16.0)\mathrm{M}\mathrm{e}\mathrm{V}\mathrm{/}{c}^2$ and $(206.3\pm 9.5\pm 18.4)\mathrm{M}\mathrm{e}\mathrm{V}$, respectively. The spin-parity of the new state is favored to be $3\mathrm{/}{2}^{-}$, and the branching fraction of $\psi (3686)\to \bar{\mathrm{\Sigma }}(2330{)}^0{\mathrm{\Sigma }}^0+c\mathrm{.}c\mathrm{.}$ is determined to be $(4.47\pm 0.58\pm 1.52)\times {10}^{-6}$. In addition, the branching fraction of $\psi (3686)\to \bar{p}{K}^{+}{\mathrm{\Sigma }}^0+c\mathrm{.}c\mathrm{.}$ is determined to be either $(2.44\pm 0.20\pm 0.08)\times {10}^{-5}$ or $(1.73\pm 0.29\pm 0.06)\times {10}^{-5}$ by considering two solutions. The first uncertainties are statistical and the second systematic.