Amplitude analysis and branching fraction measurement of the decay $D_{s}^{+} \to \pi^{+}\pi^{0}\pi^{0}$

TL;DR

This paper performs an amplitude analysis of the decay $D_{s}^{+} o ext{pi}^+ ext{pi}^0 ext{pi}^0$ using BESIII data, measuring its branching fraction and intermediate process contributions.

Contribution

It provides the first detailed amplitude analysis and absolute branching fraction measurement for this decay mode, including intermediate resonant processes.

Findings

Branching fraction of $D_{s}^{+} o ext{pi}^+ ext{pi}^0 ext{pi}^0$ is (0.50 ± 0.04 ± 0.02)%

Branching fraction of $D_{s}^{+} o f_0(980) ext{pi}^+$, $f_0(980) o ext{pi}^0 ext{pi}^0$ is (0.21 ± 0.03 ± 0.03)%

Amplitude analysis determines relative fractions and phases of intermediate processes.

Abstract

Using a data set corresponding to an integrated luminosity of 6.32~$\rm fb^{-1}$ recorded by the BESIII detector at center-of-mass energies between 4.178 and 4.226~GeV, an amplitude analysis of the decay $D_{s}^{+} \to \pi^{+}\pi^{0}\pi^{0}$ is performed, and the relative fractions and phases of different intermediate processes are determined. The absolute branching fraction of the decay $D_{s}^{+} \to \pi^{+}\pi^{0}\pi^{0}$ is measured to be $(0.50\pm 0.04_{\text{stat}}\pm 0.02_{\text{syst}})\%$. The absolute branching fraction of the intermediate process $D_{s}^{+} \to f_0(980)\pi^{+}, f_0(980)\to\pi^{0}\pi^{0}$ is determined to be $(0.21\pm 0.03_{\text{stat}}\pm 0.03_{\text{syst}})\%$.