Doubly Heavy Tetraquarks in the Chiral Quark Soliton Model

TL;DR

This paper uses the Chiral Quark Soliton Model to predict masses of heavy tetraquarks, finding that bottom tetraquarks are bound states while the charm tetraquark is slightly above the threshold.

Contribution

It introduces a novel approach by replacing heavy quarks with heavy anti-diquarks in the model to estimate tetraquark masses.

Findings

Charm tetraquark is 70 MeV above the $DD^*$ threshold.

Bottom tetraquarks are bound by approximately 140 MeV (non-strange) and 60 MeV (strange).

Heavy diquark masses are estimated using the Cornell potential.

Abstract

Chiral Quark Soliton Model has been successfully applied to describe heavy baryon spectrum, both for charm and bottom, leading to the conclusion that the heavy quark has no effect on the soliton. This suggests that replacing a heavy quark by a heavy anti-diquark $\bar{Q}\bar{Q}$ in color triplet should give a viable description of heavy tetraquarks. We follow this strategy to compute tetraquark masses. To estimate heavy diquark masses we use Cornell potential with appropriately rescaled parameters. The lightest charm tetraquark is 70 MeV above the $DD^*$ threshold. On the contrary, both non-strange and strange bottom tetraquarks are bound by approximately 140 MeV and 60 MeV, respectively.