Amplitude analysis and branching fraction measurement of the decay $D^0 \to K^0_S\pi^0\pi^0$

TL;DR

This paper performs an amplitude analysis of the decay D^0 → K_S^0 π^0 π^0 to measure its branching fraction and understand the intermediate processes involved, using data from the BESIII detector at 3.773 GeV.

Contribution

It provides the first detailed amplitude analysis and precise measurement of the branching fraction for D^0 → K_S^0 π^0 π^0 decay, identifying dominant intermediate states.

Findings

Branching fraction of D^0 → K_S^0 π^0 π^0 is (1.026 ± 0.008(stat) ± 0.009(syst))%.

Dominant intermediate process is D^0 → K* (892)^0 π^0 with a branching fraction of (4.22 ± 0.09(stat) ± 0.14(syst))×10^{-3}.

Amplitude analysis reveals relative magnitudes and phases of intermediate states.

Abstract

An amplitude analysis of the decay $D^0 \to K_S^0 \pi^0 \pi^0$ is performed to determine the relative magnitudes and phases of different intermediate processes. The analysis uses $e^+e^-$ collision data collected at the center-of-mass energy of 3.773 GeV by the BESIII detector corresponding to an integrated luminosity of 20.3 $\rm fb^{-1}$. The absolute branching fraction of $D^0 \to K^0_S \pi^0 \pi^0$ is measured to be $(1.026 \pm 0.008_{\rm{stat.}} \pm 0.009_{\rm{syst.}}) \%$. The dominant intermediate process is $D^0 \to \bar{K}^{*}(892)^{0}(\to K^0_S \pi^0) \pi^0$, with a branching fraction of $(4.22\pm0.09_{\rm{stat.}}\pm0.14_{\rm{syst.}})\times 10^{-3}$.