# String dynamics and metastability of fully-heavy tetraquarks

## TL;DR

This paper investigates the stability of fully-heavy tetraquarks using quark models, finding that full-charm and full-beauty configurations are unbound, but mixed heavy quark states might be more stable with alternative confinement models.

## Contribution

It provides a rigorous four-body analysis of fully-heavy tetraquarks and explores the potential for stability in mixed heavy quark configurations with string-inspired interactions.

## Key findings

- Full-charm and full-beauty tetraquarks are unbound in current models.
- Mixed heavy tetraquarks may be more stable with alternative confinement.
- Standard models do not predict stable fully-heavy tetraquarks.

## Abstract

Multiquark states have been advocated to explain recent experimental data in the heavy-light sector, and there are already speculations about multiquarks containing only heavy quarks and antiquarks. With a rigorous treatment of the four-body problem in current quark models, full-charm $(cc\bar c\bar c)$ and full-beauty $(bb\bar b\bar b)$ tetraquarks are found to be unbound. Thus their stability should rely on more subtle effects that are not included in the simple picture of constituent quarks. The case of $(bc\bar b\bar c)$ might be more favorable if the naive color-additive model of confinement is replaced by a string-inspired interaction.