A non-parametric approach to measuring the K−π+ amplitudes in D+→K−K+π+ decay

Using a large sample of D+→K−K+π+ decays collected by the FOCUS photoproduction experiment at Fermilab, we present the first non-parametric analysis of the K−π+ amplitudes in D+→K−K+π+ decay. The technique is similar to the technique used for our non-parametric measurements of the D+→K¯∗0e+ν form factors. Although these results are in rough agreement with those of E687, we observe a wider S-wave contribution for the K¯0∗0(1430) contribution than the PDG [W.-M. Yao, et al., J. Phys. G 33 (2006) 1], world average mass and width. We have some weaker evidence for the existence of a new, D-wave component at low values of the K−π+ mass.