The $a_0(980)$ physics in semileptonic $D^0$ and $D^+$ decays

TL;DR

This paper investigates the role of the $a_0(980)$ meson in semileptonic $D$ meson decays, proposing a scenario where $a_0(980)$ has no quark-antiquark component, and discusses implications for experimental observations.

Contribution

It introduces a model where $a_0(980)$ lacks a $qar q$ component and analyzes its impact on decay distributions, providing a new perspective on the meson's internal structure.

Findings

Proposes a variant of the $ ext{ηπ}$ invariant mass distribution without $qar q$ component.

Suggests experimental signatures for the absence of $qar q$ in $a_0(980)$.

Connects decay analysis with meson internal structure hypotheses.

Abstract

The decays $D^0\to d\bar u\,e^+\nu\to a^-_0(980)\, e^+\nu\to\pi^-\eta\, e^+\nu$ and $D^+\to d\bar d\,e^+\nu\to a^0_0(980)\, e^+\nu\to\pi^0\eta\, e^+\nu$ (and the charge conjugated ones) is the direct probe of the two-quark components in the $a^\pm_0(980)$ and $a^0_0(980)$ wave functions. Recent BESIII experiment is the first step in experimental study of these decays. We present a possible variant of $\eta\pi$ invariant mass distribution when $a_0(980)$ has no $q\bar q$ component at all.