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

Abstract

From a sample of 848 $\pm$ 44 $D_s^+ \to π^- π^+ π^+$ decays, we find $Γ(D_s^+ \to π^- π^+ π^+) / Γ(D_s^+ \to ϕπ^+) = 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 $ρ^0(770)π^+$, $ρ^0(1450)π^+$, $f_0(980)π^+$, $f_2(1270)π^+$, and $f_0(1370)π^+$. We present also the values obtained for masses and widths of the resonances $f_0(980)$ and $f_0(1370)$.