Holographic Hadro-Quarkonium

TL;DR

This paper models certain charmonium-like resonances as bound states of heavy quarkonium within excited light mesons using holographic QCD, predicting their existence at high light meson spins and analyzing their decay suppression.

Contribution

It introduces a holographic QCD model for heavy quarkonium-light meson bound states and predicts their existence at large light meson spins.

Findings

Bound states of charmonium inside excited light mesons are predicted at high spins.

Decay into open heavy flavor mesons is suppressed due to tunneling effects.

The model's predictions align with observed decay suppression patterns.

Abstract

We consider the recently suggested model for some resonances near the open charm threshold as bound states of charmonium inside excited light mesons. It is argued in the soft-wall holographic model of QCD that such states of heavy quarkonium necessarily exist at sufficiently large spin of the light meson. The bound state is provided by the dilaton exchange through the 5D bulk. We also argue that the decay of such bound systems into mesons with open heavy flavors due to splitting of the heavy quarkonium can be treated as semiclassical tunneling and is suppressed. This behavior is in agreement with the known relative suppression of the decay of the discussed charmonium-like resonances into channels with D mesons.