Observation of the decay $psi(3686)$ $rightarrow$ $LambdabarSigma^{pm}pi^{mp}+c.c.$

Using a sample of $1.06times10^{8}$ $psi(3686)$ events collected with the BESIII detector, we present the first observation of the decays of $psi(3686)$ $rightarrow$ $LambdabarSigma^{+}pi^{-}+c.c.$ and $psi(3686)$ $rightarrow$ $LambdabarSigma^{-}pi^{+}+c.c.$. The branching fractions are measured to be $mathcal{B}(psi(3686) rightarrow LambdabarSigma^{+}pi^{-} + c.c.)=(1.40pm 0.03 pm 0.13)times10^{-4}$ and $mathcal{B}(psi(3686) rightarrow LambdabarSigma^{-}pi^{+}+c.c.)=(1.54pm 0.04 pm 0.13)times10^{-4}$, where the first errors are statistical and the second ones systematic.