Semileptonic decays $D\to\eta\pi e^+\nu_e$ in the $a_0(980)$ region

TL;DR

This paper investigates the production mechanism and internal structure of the $a_0(980)$ resonance in $D$ meson decays to $ o ext{eta} ext{pi} e^+ u_e$, proposing that mass spectra features can reveal its four-quark nature.

Contribution

It introduces a scheme to analyze the $a_0(980)$ production in $D$ decays, linking spectral features to its four-quark structure.

Findings

Mass spectra features can indicate the four-quark nature of $a_0(980)$.

Characteristic spectral shapes serve as indicators of the resonance's internal structure.

The proposed scheme helps distinguish production mechanisms of light scalar mesons.

Abstract

The mechanism of the four-quark production of the light scalar isovector four-quark state $a_0(980)$ in the $D\to\eta\pi e^+\nu_e$ decays is discussed. It is shown that the characteristic features of the shape of the $\eta\pi$ mass spectra expected in our scheme can serve as the indicator of the production mechanism and internal structure of the $a_0(980)$ resonance.