Dispersion-theoretical analysis of the D^+ --> K^- pi^+ pi^+ Dalitz plot

TL;DR

This paper applies dispersion theory to analyze the $D^+ o K^- \pi^+\pi^+$ decay Dalitz plot, ensuring all physical constraints are met and fitting experimental data to understand final-state interactions.

Contribution

It introduces a dispersion-theoretical formalism for three-body charm decays that respects analyticity and unitarity, fitting phase shifts to experimental Dalitz plot data.

Findings

Successful description of Dalitz plot data from CLEO and FOCUS

Insights into phase motions of resonant and nonresonant amplitudes

Provides input for future CP violation studies in charm decays

Abstract

We study the Dalitz plot of the Cabibbo-favored charmed-meson decay $D^+\to K^-\pi^+\pi^+$ using dispersion theory. The formalism respects all constraints from analyticity and unitarity, and consistently describes final-state interactions between all three decay products. We employ pion-pion and pion-kaon phase shifts as input, and fit the pertinent subtraction constants to Dalitz plot data by the CLEO and FOCUS collaborations. Phase motions of resonant as well as nonresonant amplitudes are discussed, which should provide crucial input for future studies of CP violation in similar three-body charm decays.