New Charm Spectroscopy: Insights from Theory

TL;DR

This paper analyzes recent charm meson observations, comparing decay modes and theoretical models to identify meson states and interpret their properties within quantum chromodynamics.

Contribution

It provides theoretical insights into charm meson decays and identifies specific mesons as radial excitations or ordinary states based on decay analysis.

Findings

D_{sJ}(2317) and D_{sJ}(2460) are consistent with being ordinary c-sbar states.

D_{sJ}(2710) is identified as the first radial excitation of D_s^*.

The nature of D_{sJ}(2860) remains uncertain.

Abstract

We discuss several new observations of mesons with open charm. In particular, we consider $D_{sJ}(2317)$ and $D_{sJ}(2460)$ and compare their isospin violating decays into $D^{(*)}_s \pi$ to the radiative decays analysed using light-cone QCD sum rules. The results support the interpretation of these two mesons as ordinary $c{\bar s}$ states. In the case of $D_{sJ}(2860)$ and $D_{sJ}(2710)$ we compute the strong decays in the heavy quark limit. Comparison of the results with recent measurements of the BaBar Collaboration leads to identify $D_{sJ}(2710)$ with the first radial excitation of $D_s^*$, while the identification is still uncertain in the case of $D_{sJ}(2860)$.