Paper detail

Measurement of the $η\to 3π^{0}$ slope parameter $α$ with the KLOE detector

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