Spectrum of $cc\bar{b}\bar{b}$, $bc\bar{c}\bar{c}$, and $bc\bar{b}\bar{b}$ Tetraquark States in the Dynamical Diquark Model

TL;DR

This paper uses the dynamical diquark model and lattice-calculated Born-Oppenheimer potentials to predict the mass spectra of various heavy tetraquark states, identifying potential bound states and their relation to meson thresholds.

Contribution

It provides the first mass spectrum predictions for $cc\bar{b}\bar{b}$, $bc\bar{c}\bar{c}$, and $bc\bar{b}\bar{b}$ tetraquarks using a lattice-informed dynamical diquark model with the Born-Oppenheimer approximation.

Findings

The $cc\bar{b}\bar{b}$ ground state may be a bound state below meson thresholds.

Masses of $bc\bar{c}\bar{c}$ and $bc\bar{b}\bar{b}$ are above their respective thresholds.

The model predicts specific mass spectra for these tetraquark states.

Abstract

The dynamical diquark model assumes that exotic hadrons can be formed from colored diquarks. This model asserts a multiquark exotic state composed of a compact diquark $\delta$ and antidiquark $\bar{\delta}$ for a tetraquark interacting through a gluonic field of finite extent. Using Born-Oppenheimer (BO) approximation and BO potential calculated numerically on the lattice, we study mass spectra of $S-$wave $cc\bar{b}\bar{b}$, $bc\bar{c}\bar{c}$, and $bc\bar{b}\bar{b}$ tetraquark systems in the basis of diquark spins. We assume that colour-antitriple diquark and colour-triplet antidiquark form tetraquark state. The predicted mass spectrum for ground state of $cc\bar{b}\bar{b}$ is found to be lower then their corresponding two-meson thresholds. This system may be a candidate for bound state. Masses of $bc\bar{c}\bar{c}$ and $bc\bar{b}\bar{b}$ tetraquark states are found to be above than the corresponding two-meson thresholds.