Study of light scalar mesons through $D_s^+ \to \pi^0 \pi^0 e^+ \nu_e$ and $K_S^0 K_S^0 e^+ \nu_e$ decays

TL;DR

This paper reports the first measurement of the decay $D_s^+ o f_0(980) e^+ u_e$ with $f_0(980) o \pi^0 \pi^0$, providing new insights into the structure of light scalar mesons.

Contribution

It presents the first measurement of the decay involving the $f_0(980)$ meson and sets upper limits on related decay modes, advancing understanding of light scalar meson structures.

Findings

Measured the branching fraction of $D_s^+ o f_0(980) e^+ u_e$ as $(7.9 imes 10^{-4})$

Set upper limits on $D_s^+ o f_0(500) e^+ u_e$ and $D_s^+ o K_S^0 K_S^0 e^+ u_e$ decays

Provided data that constrains models of light scalar mesons

Abstract

Using 6.32~fb$^{-1}$ of $e^+e^-$ collision data recorded by the BESIII detector at center-of-mass energies between $4.178$ to $4.226$ GeV, we present the first measurement of the decay $D_s^+\to f_0(980)e^+\nu_e,\,f_0(980)\to \pi^0\pi^0$. The product branching fraction of $D_s^+\to f_0(980)e^+\nu_e,\,f_0(980)\to \pi^0\pi^0$ is measured to be $(7.9\pm1.4_{\rm stat} \pm0.3_{\rm syst})\times 10^{-4}$, with a statistical significance of $7.8\sigma$. Furthermore, the upper limits on the product branching fractions of $D_s^+\to f_0(500)e^+\nu_e$ with $f_0(500)\to \pi^0\pi^0$ and the branching fraction of $D_s^+\to K_{S}^{0}K_{S}^{0}e^+\nu_e$ are set to be $7.3\times 10^{-4}$ and $3.8\times 10^{-4}$ at 90\% confidence level, respectively. Our results provide valuable inputs to the understanding of the structures of light scalar mesons.