Measurement of the charge asymmetry of the Dalitz plot parameters for K ± → π ± π 0 π 0 decays

Abstract

The g, h, and k Dalitz plot parameters, which are coefficients in a series expansion of the squared module of the matrix element |M (u, v)| 2 ∝ 1+gu+hu 2 +kv 2 (u, v are invariant variables), have been measured for K ± → π ± π 0 π 0 decays using 35 GeV /c hadron beams at the IHEP (Protvino) accelerator. Dependences of parameters and fit quality on the π 0 π 0 mass cut were investigated. The results point to the important role of π + π − → π 0 π 0 charge exchange scattering near the π 0 π 0 mass threshold. The comparison of our data with previous measurements is presented.

Kaon decay studies at CERN SPS in the last decades

“…The results are one order of magnitude more precise than previous measurements and are consistent with the predictions of the SM, in particular, with the next-to-leading order ChPT calculation [20] [15] are deˇned mainly by the above NA48/2 results. The only preceding result that is also used currently for PDG average, A n g = (2 ± 18 stat ± 5 syst ) • 10 −4 , is published in 2005 [21].…”