Model-independent measurement ofS-waveK−π+systems usingD+→K<

Abstract

A model-independent partial-wave analysis of the S-wave component of the K system from decays of D mesons to the three-body K ÿ final state is described. Data come from the Fermilab E791 experiment. Amplitude measurements are made independently for ranges of K ÿ invariant mass, and results are obtained below 825 MeV=c 2 , where previous measurements exist only in two mass bins. This method of parametrizing a three-body decay amplitude represents a new approach to analyzing such decays. Though no model is required for the S-wave, a parametrization of the relatively well-known reference P-and D-waves, optimized to describe the data used, is required. In this paper, a Breit-Wigner model is adopted to describe the resonances in these waves. The observed phase variation for the S-, P-, and D-waves do not match existing measurements of I 1 2 K ÿ scattering in the invariant mass range in which scattering is predominantly elastic. If the data are mostly I 1 2 , this observation indicates that the Watson theorem, which requires these phases to have the same dependence on invariant mass, may not apply to these decays without allowing for some interaction with the other pion. The production rate of K ÿ from these decays, if assumed to be predominantly I 1 2 , is also found to have a significant dependence on invariant mass in the region above 1:25 GeV=c 2. These measurements can provide a relatively model-free basis for future attempts to determine which strange scalar amplitudes contribute to the decays.

Amplitude analysis of theD+→KS0π+πAblikim1, Ачасов2, Ai3 et al. 2014Phys. Rev. DSelf Cite18040View full textAdd to dashboardCite

“…[7], to confirm the results. The Kπ S-wave can be well described by aκ, aK Ã 0 ð1430Þ, and a nonresonant component.…”

“…A large contribution from a Kπ S-wave intermediate state has been observed in earlier experiments including MARKIII [2], NA14 [3], E691 [4], E687 [5], E791 [6,7], and CLEO-c [8] in the D þ → K − π þ π þ decay. Both E791 and CLEO-c interpreted their data with a modelindependent partial wave analysis (MIPWA) and found a phase shift at low Kπ mass to confirm theκπ component.…”

“…An attempt to mitigate the model dependence for the D þ → K − π þ π þ decay under study is described in [7]. Here, we apply this model-independent partial wave analysis (MIPWA) technique as a cross-check of our model D for the contributions of K 0 S π 0 S-wave.…”

Deep inside the pion. Reconciling QCD theory with data

“…The experimental data are taken from [34] (diamonds) and [33] (triangles). (b): Comparison with the E791 data [35] on diffractive di-jet production of the BMS "bunch" (shaded strip), the asymptotic DA (solid line), and the CZ (dashed line) model, using the convolution approach of [36].…”

S -wave Kπ contributions to the hadronic charmonium B decays in the perturbative QCD approach

“…Detailed discussions of the S-wave Kπ systems in the isobar model, K-matrix model, and model-independent partial wave analysis method can be found in Refs. [45][46][47][48]. In this work, we parametrize the timelike scalar form factor F s ðω 2 Þ for the S-wave Kπ systems by the LASS line shape [32], which has been widely adopted in the experimental data analysis; its expression is given as [4,49] …”