Further study of $D^+_s$ decays into $\pi^- \pi^+ \pi^+$

TL;DR

This paper analyzes the decay of D_s+ into three pions using Dalitz plots and various partial wave models, emphasizing scalar mesons and their contributions, especially the f0(980) resonance.

Contribution

It compares different partial wave approaches, including K-matrix and Breit-Wigner models, to better understand scalar meson contributions in D_s+ decays.

Findings

f0(980) is the most significant scalar resonance

Adding f0(1500) improves fit, while f0(1370) and f0(1710) do not

Scalar wave phase motion spans approximately 270 degrees

Abstract

A Dalitz plot analysis of the OZI rule violating decay $D^+_s$ into $\pi^- \pi^+ \pi^+$ is presented using different partial wave approaches. Scalar and vector waves are described by $K$-matrices; their production is parameterized in a $P$-vector approach. Alternatively, Breit-Wigner amplitudes and Flatt\'e parametrization are used. Special emphasis is devoted to scalar mesons. The $f_0(980)$ resonance provides the most significant contribution. Adding $f_0(1500)$ to the scalar wave leads to an acceptable fit while introduction of $f_0(1370)$ and/or $f_0(1710)$ does not lead to significant improvements. A scan of the scalar wave optimizes for $M=1452\pm 22$ MeV/c$^2$. When $f_0(1710)$ is added, the mass uncertainty increases, and the fit yields $M=1470\pm 60$ MeV/c$^2$ which is fully compatible with the nominal $f_0(1500)$ mass. The scalar wave seems to exhibit a phase motion of 270$^{\circ}$ units in the mass range from 1200 to 1650 MeV/c$^2$.