Measurement of the slope parameter \alpha for the \eta\to 3\pi^0 decay at KLOE

We report a preliminary measurement of the slope parameter $\alpha$ for the $\eta \to 3\text{piz}$ decay carried out with KLOE at DA$\mathrm{\Phi }$NE; where $\alpha$ is the parameter describing the energy dependence of the square of the matrix element for this decay. By fitting the event density in the Dalitz plot with a collected statistic of 420 pb${}^{-1}$ we determine $\alpha = -0.027 \pm 0.004 (stat) ^{+0.004}_{-0.006} (syst)$. This result is consistent with current chiral perturbation theory calculations within the unitary approach.