Measurement of $chi_{cJ}$ decaying into $pbar{n}pi^{-}$ and $pbar{n}pi^{-}pi^{0}$

Using a data sample of $1.06 times 10^{8}$ $psip$ events collected with the BESIII detector in 2009, the branching fractions of $chi_{cJ}to pbar{n}pi^{-}$ and $chi_{cJ}to pbar{n}pi^{-}pi^{0}$ ($J$=0,1,2) are measured{Throughout the text, inclusion of charge conjugate modes is implied if not stated otherwise.}. The results for $chi_{c0}to pbar{n}pi^{-}$ and $chi_{c2}to pbar{n}pi^{-}$ are consistent with, but much more precise than those of previous measurements. The decays of $chi_{c1}to pbar{n}pi^{-}$ and $chi_{cJ}to pbar{n}pi^{-}pi^{0}$ are observed for the first time.