Heavy tetraquarks in the relativistic quark model

TL;DR

This paper reviews the calculation of heavy tetraquark masses using a relativistic quark model, employing a diquark-antidiquark framework, and compares predictions with experimental data, suggesting possible tetraquark candidates.

Contribution

It introduces a relativistic quark model with a diquark-antidiquark picture to predict heavy tetraquark masses, incorporating internal diquark structure and form factors, and compares results with experimental observations.

Findings

Predicted heavy tetraquark masses align with some experimental signals.

Many tetraquark candidates are identified in the mass spectrum.

The model supports interpreting certain LHCb structures as $cc\bar c\bar c$ tetraquarks.

Abstract

We give a review of the calculations of the masses of tetraquarks with two and four heavy quarks in the framework of the relativistic quark model based on the quasipotential approach and QCD. The diquark-antidiquark picture of heavy tetraquarks is used. The quasipotentials of the quark-quark and diquark-antidiquark interactions are constructed similarly to the previous consideration of mesons and baryons. Diquarks are considered in the colour triplet state. It is assumed that the diquark and antidiquark interact in the tetraquark as a whole and the internal structure of the diquarks is taken into account by the calculated form factor of the diquark-gluon interaction. All parameters of the model are kept fixed from our previous calculations of meson and baryon properties. A detailed comparison of the obtained predictions for heavy tetraquark masses with available experimental data is given. Many candidates for tetraquarks are found. It is argued that the structures in the di-$J/\psi$ mass spectrum observed recently by the LHCb Collaboration can be interpreted as $cc\bar c\bar c$ tetraquarks.