Study of ${\chi }_{cJ}$ decaying into $\varphi$ $K^{\ast }(892)$ $\bar{K}$

Using a data sample of 106 million $\psi (3686)$ events collected with the BESIII detector operated at the BEPCII storage ring, we study for the first time the decay ${\chi }_{cJ}\to \varphi K_S^0{K}^{\pm }{\pi }^{\mp }$ and ${\chi }_{cJ}\to \varphi K^{+}{K}^{-}{\pi }^0$ in the E1 radiative transition $\psi (3686)\to \gamma {\chi }_{cJ}$. The decays are dominated by the three-body decay ${\chi }_{cJ}\to \varphi K^{\ast }(892)\bar{K}$. We measure branching fractions for this reaction via the neutral and charged $K^{\ast }(892)$ and find them consistent with each other within the expectation of isospin symmetry. In the $K\bar{K}\pi$ invariant mass distribution a structure near the $K^{\ast }(892)\bar{K}$ mass threshold is observed, and the corresponding mass and width are measured to be $1412\pm4($\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.}$)\pm8($\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{.}$) $\mathrm{M}\mathrm{e}\mathrm{V}$/c^2$and$\Gamma$=$84\pm12($\mathrm{s}\mathrm{t}\mathrm{a}\mathrm{t}\mathrm{.}$)\pm40($\mathrm{s}\mathrm{y}\mathrm{s}\mathrm{.}$) $\mathrm{M}\mathrm{e}\mathrm{V}$$,respectively\mathrm{.}Theobservedstatefavorsanassignmenttothe$h_1(1380)$,consideringitspossible$J^{PC}$ and comparing its mass, width and decay mode to those reported in the Particle Data Group.