Study of the $D^+_s \to \pi^- \pi^+ \pi^+$ decay and measurement of $f_0$ masses and widths

TL;DR

This paper analyzes the decay of D_s^+ into three pions using a Dalitz plot, measuring resonance contributions and determining the masses and widths of f_0(980) and f_0(1370).

Contribution

It provides the first detailed Dalitz plot analysis of D_s^+ → π^- π^+ π^+ decay and measures key resonance parameters.

Findings

Significant contributions from multiple resonances including ρ^0(770), ρ^0(1450), f_0(980), f_2(1270), and f_0(1370).

Measured ratio of decay widths: 0.245 ± 0.028^{+0.019}_{-0.012}.

Determined masses and widths of f_0(980) and f_0(1370).

Abstract

From a sample of 848 $\pm$ 44 $D_s^+ \to \pi^- \pi^+ \pi^+$ decays, we find $\Gamma(D_s^+ \to \pi^- \pi^+ \pi^+) / \Gamma(D_s^+ \to \phi \pi^+) = 0.245 \pm 0.028^{+0.019}_{-0.012} $. Using a Dalitz plot analysis of this three body decay, we find significant contributions from the channels $\rho^0(770)\pi^+$, $\rho^0(1450)\pi^+$, $f_0(980)\pi^+$, $f_2(1270)\pi^+$, and $f_0(1370)\pi^+$. We present also the values obtained for masses and widths of the resonances $f_0(980)$ and $f_0(1370)$.