Measurement of the $etato 3pi^{0}$ slope parameter $alpha$ with the KLOE detector

We present a measurement of the slope parameter $alpha$ for the $etato 3pi^{0}$ decay, with the KLOE experiment at the DA$Phi$NE $phi$-factory, based on a background free sample of $sim$ 17 millions $eta$ mesons produced in $phi$ radiative decays. By fitting the event density in the Dalitz plot we determine $alpha = -0.0301 pm 0.0035,stat;_{-0.0035}^{+0.0022},syst,$. The result is in agreement with recent measurements from hadro- and photo-production experiments.