# Nature of the D_0 meson in the D pi scattering with chiral symmetry

## TL;DR

This paper investigates the scalar D_0 meson using chiral symmetry, modeling it as a resonance in D pi scattering, and finds its properties are robust against changes in chiral condensate, emphasizing its molecular nature.

## Contribution

It constructs a chiral-symmetric D pi scattering amplitude showing the D_0 as a chiral partner and highlights the meson's molecular dressing effects.

## Key findings

- D_0 appears as an s-wave resonance in D pi scattering.
- Properties of D_0 are insensitive to chiral condensate reduction.
- D_0's spectral function and pole are influenced by D pi molecular components.

## Abstract

We study the nature of the scalar D_0 meson from the viewpoint of chiral symmetry. With the linear representation of chiral symmetry, we construct the D pi scattering amplitude satisfying the chiral low-energy theorem, in which the D_0 meson appears as an s-wave resonance. We show that the properties of the D_0 meson can be successfully reproduced as the chiral partner of the D meson coupled with the D pi scattering states. At the same time, we find that the spectral function and the pole position of D_0 are not very sensitive to the reduction of the chiral condensate, indicating the importance of the dressing of the bare state by the D pi molecular component.