# The Dynamical Diquark Model: First Numerical Results

## TL;DR

This paper presents the first numerical predictions of the dynamical diquark model for multiquark exotic hadrons, using lattice-calculated potentials to solve Schrödinger equations and predict masses of exotic states consistent with experimental observations.

## Contribution

It provides the first numerical results for the dynamical diquark model, including mass predictions and decay analysis, advancing understanding of multiquark exotic hadrons.

## Key findings

- Predicted exotic states match observed charmoniumlike states.
- Identified states below the charmonium-plus-nucleon threshold.
- Proposed relaxation of decay selection rules improves model consistency.

## Abstract

We produce the first numerical predictions of the dynamical diquark model of multiquark exotic hadrons. Using Born-Oppenheimer potentials calculated numerically on the lattice, we solve coupled and uncoupled systems of Schroedinger equations to obtain mass eigenvalues for multiplets of states that are, at this stage, degenerate in spin and isospin. Assuming reasonable values for these fine-structure splittings, we obtain a series of bands of exotic states with a common parity eigenvalue that agree well with the experimentally observed charmoniumlike states, and we predict a number of other unobserved states. In particular, the most suitable fit to known pentaquark states predicts states below the charmonium-plus-nucleon threshold. Finally, we examine the strictest form of Born-Oppenheimer decay selection rules for exotics and, finding them to fail badly, we propose a resolution by relaxing the constraint that exotics must occur as heavy-quark spin-symmetry eigenstates.