Doubly heavy tetraquarks in a chiral-diquark picture

TL;DR

This paper investigates the energy spectrum of doubly heavy tetraquarks using a chiral-diquark model, identifying bound states for $T_{bb}$ and analyzing mass changes under chiral symmetry restoration.

Contribution

It introduces a potential chiral-diquark model to study doubly heavy tetraquarks as three-body systems, providing new insights into their bound states and mass behavior.

Findings

Several $T_{bb}$ bound states identified.

No deep bound states for $T_{cc}$ and $T_{cb}$.

Masses change under chiral symmetry restoration.

Abstract

Energy spectrum of doubly heavy tetraquarks, $T_{QQ}$ ($QQ \bar{q} \bar{q}$ with $Q = c, b$ and $q = u, d, s$), is studied in the potential chiral-diquark model. Using the chiral effective theory of diquarks and the quark-diquark-based potential model, the $T_{bb}$, $T_{cc}$, and $T_{cb}$ tetraquarks are described as a three-body system composed of two heavy quarks and an antidiquark. We find several $T_{bb}$ bound states, while no $T_{cc}$ and $T_{cb}$ (deep) bound state is seen. We also study the change of the $T_{QQ}$ tetraquark masses under restoration of chiral symmetry.