Dalitz plot analysis for η → π⁺π^-π⁰ at KLOE

We present the status of an ongoing analysis of the η → π⁺π^-π⁰ Dalitz plot, as well as preliminary results for the Dalitz plot parameters. The η meson is produced by the radiative decay of : e⁺e^- → φ → ηγ(rec) → π⁺π^-π⁰γ(rec) → π⁺π^-γγγ(rec). Consequently the final state has 3 photons and 2 charged tracks with opposite charge. Events are selected by requiring at least 3 prompt neutral clusters in the calorimeter and at least a positive and a negative track in the drift chamber. This work is a new analysis of ∼ 1.7 fb^-1 data taken at the DAΦNE φ-factory with the KLOE detector in 2004-2005. The data set is larger to overcome some limitations of the previous analysis. A new selection scheme has been used. To reduce systematic effects, the Monte Carlo description of the detector has been improved and any possible bias due to the event classification filter, that organizes data in different output files, has been studied on pre-scaled, unclassified events