Measurement of the quadratic slope parameter in the KL→3π0 decay Dalitz plot

Abstract A value of (−6.1±0.9 stat ±0.5 syst )×10 −3 is obtained for the quadratic slope parameter h in the K L →3 π 0 decay Dalitz plot at the NA48 experiment at the CERN SPS. The result is based on 14.7×10 6 fully reconstructed K L →3 π 0 →6 γ decays. This is the most precise measurement of any of the Dalitz plot slope parameters in the charged and neutral kaon decays so far.