η-decays into three pions

The branching ratios Γ(η → 3π0)Γ(η → π+π−π0) = 1.44 ± 0.09 ± 0.10 and Γ(η → γγ)Γ(η → π+π−π0) = 1.78 ± 0.10 ± 0.13 have been determined using the Crystal Barrel detector at LEAR. The latter ratio yields a partial width of Γ(η → π+π−π0) = 0.26 ± 0.03 keV using the known value for Γ(η → γγ). The η → π+π−π0) Dalitz plot is compared to the predictions of chiral perturbation theory.