Triply heavy tetraquark states

TL;DR

This study uses an extended chromomagnetic model to analyze the mass spectrum of S-wave triply heavy tetraquarks, revealing favored color configurations and predicting narrow, potentially observable axial-vector states above meson thresholds.

Contribution

It provides a systematic mass spectrum analysis of triply heavy tetraquarks using an extended chromomagnetic model, highlighting favored color configurations and decay properties.

Findings

Color interaction favors different configurations depending on quark content.

No stable states below two pseudoscalar meson thresholds.

Potential narrow axial-vector states just above meson thresholds.

Abstract

In the framework of an extended chromomagnetic model, we systematically study the mass spectrum of the $S$-wave $qQ\bar{Q}\bar{Q}$ tetraquarks. Their mass spectra are mainly determined by the color interaction. For the $qc\bar{c}\bar{c}$, $qb\bar{c}\bar{c}$ and $qb\bar{b}\bar{b}$ tetraquarks, the color interaction favors the color-sextet $\ket{(qQ)^{6_{c}}(\bar{Q}\bar{Q})^{\bar{6}_{c}}}$ configuration over the color-triplet $\ket{(qQ)^{\bar{3}_{c}}(\bar{Q}\bar{Q})^{3_{c}}}$ one. But for the $qc\bar{b}\bar{b}$ tetraquarks, the color-triplet configuration is favored. We find no stable states which lie below the thresholds of two pseudoscalar mesons. The lowest axial-vector states with the $qQ\bar{b}\bar{b}$ flavor configuration may be narrow. They lie just above the thresholds of two pseudoscalar mesons, but cannot decay into these channels because of the conservation of the angular momentum and parity.