Implication of chiral symmetry for the heavy-light meson spectroscopy

TL;DR

This paper explains the puzzling properties of certain charm mesons using chiral effective theory and lattice simulations, showing they are dynamically generated states rather than simple quark-antiquark pairs.

Contribution

It demonstrates that positive-parity charm mesons are dynamically generated through nonperturbative Goldstone boson interactions, challenging traditional quark model interpretations.

Findings

The $D_{s0}^*(2317)$ and $D_{s1}(2460)$ are explained as nonperturbative scattering states.

The lowest positive parity nonstrange scalar charm mesons should be replaced by two states.

The amplitudes align with experimental decay data.

Abstract

Many hadronic states observed since 2003, especially for the positive-parity charm-strange states $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$, do not conform with the conventional quark model expectations and raise various puzzles in charm meson spectroscopy. We demonstrate that those puzzles find a natural solution thanks to the recent development of chiral effective theory and Lattice simulations. The existence of the $D_{s0}^\ast (2317)$ and $D_{s1}(2460)$ are attributed to the nonperturbative dynamics of Goldstone bosons scattering off $D$ and $D^\ast$ mesons. It indicates that the lowest positive parity nonstrange scalar charm mesons, the $D_0^\ast(2400)$ in the Review of Particel Physics, should be replaced by two states. The well constructed amplitudes are fully in line with the high quality data on the decays $B^-\to D^+\pi^-\pi^-$ and $D_s^0\to \bar{D}^0K^-\pi^+$. This implies that the lowest positve-parity states are dynamically generated rather than conventional quark-antiquark states. This pattern has also been established for the scalar and axial-vector mesons made from light quarks ($u$, $d$ and $s$ quarks).