Study of the decay $D^+\to K^*(892)^+ K_S^0$ in $D^+\to K^+ K_S^0 \pi^0$

TL;DR

This paper presents the first amplitude analysis of the decay $D^+ o K^+ K_S^0 \pi^0$, revealing the dominant $K^*(892)^+ K_S^0$ component and significantly improving the measurement precision of its branching fraction.

Contribution

It provides the first amplitude analysis of this decay mode and improves the precision of the branching fraction measurement.

Findings

$K^*(892)^+ K_S^0$ component is dominant with 57.1% fraction.

Branching fraction $ imes 10^{-3}$ is measured as 8.69 with improved precision.

Analysis enhances understanding of singly Cabibbo-suppressed $D^+$ decays.

Abstract

Based on an $e^{+}e^{-}$ collision data sample corresponding to an integrated luminosity of 2.93 $\mathrm{fb}^{-1}$ collected with the BESIII detector at $\sqrt{s}=3.773 \mathrm{GeV}$, the first amplitude analysis of the singly Cabibbo-suppressed decay $D^{+}\to K^+ K_S^0 \pi^0$ is performed. From the amplitude analysis, the $K^*(892)^+ K_S^0$ component is found to be dominant with a fraction of $(57.1\pm2.6\pm4.2)\%$, where the first uncertainty is statistical and the second systematic. In combination with the absolute branching fraction $\mathcal{B}(D^+\to K^+ K_S^0 \pi^0)$ measured by BESIII, we obtain $\mathcal{B}(D^+\to K^*(892)^+ K_S^0)=(8.69\pm0.40\pm0.64\pm0.51)\times10^{-3}$, where the third uncertainty is due to the branching fraction $\mathcal{B}(D^+\to K^+ K_S^0 \pi^0)$. The precision of this result is significantly improved compared to the previous measurement.