Observation of $eta^{prime}topi^{+}pi^{-}pi^{+}pi^{-}$ and $eta^{prime}topi^{+}pi^{-}pi^{0}pi^{0}$

Using a sample of $1.3times 10^9$ $J/psi$ events collected with the BESIII detector, we report the first observation of $eta^{prime}topi^{+}pi^{-}pi^{+}pi^{-}$ and $eta^{prime}topi^{+}pi^{-}pi^{0}pi^{0}$. The measured branching fractions are $mathcal{B}$($eta^{prime}topi^{+}pi^{-}pi^{+}pi^{-}$) = $(8.53pm0.69({rm stat.})pm0.64({rm syst.}))times10^{-5}$ and $mathcal{B}$($eta^{prime}topi^{+}pi^{-}pi^{0}pi^{0}$) = $(1.82pm0.35({rm stat.})pm0.18({rm syst.}))times10^{-4}$, which are consistent with theoretical predictions based on a combination of chiral perturbation theory and vector-meson dominance.