Doubly heavy tetraquark states in the constituent quark model using diffusion Monte Carlo method

TL;DR

This study employs the diffusion Monte Carlo method within different constituent quark models to investigate doubly heavy tetraquark states, revealing bound states with significant binding energies and providing new insights into their structure.

Contribution

It introduces the use of the diffusion Monte Carlo method to analyze doubly heavy tetraquarks across multiple quark models, highlighting the existence of bound states with larger binding energies.

Findings

AL1/AP1 model yields energies near the $DD^*$ threshold.

Chiral model predicts deeply bound tetraquark states.

Several doubly heavy tetraquark systems are confirmed to have bound states.

Abstract

We use the diffusion Monte Carlo method to calculate the doubly heavy tetraquark $T_{cc}$ system in two kinds of constituent quark models, the pure constituent quark model AL1/AP1 and the chiral constituent quark model. When the discrete configurations are complete and no spatial clustering is preseted, the AL1/AP1 model gives an energy of $T_{cc}$ close to the $DD^*$ threshold, and the chiral constituent quark model yields a deeply bound state. We further calculate all doubly heavy tetraquark systems with $J^P=0^+,1^+,2^+$, and provide the binding energies of systems with bound states. The $I(J^P)=0(0^+)$ $bc\bar{n}\bar{n}$, $0(1^+)$ $bb\bar{n}\bar{n}$, $0(1^+)$ $bc\bar{n}\bar{n}$, $\frac{1}{2}(1^+)$ $bb\bar{s}\bar{n}$ systems have bound states in all three models. Since the DMC method has almost no restriction on the spatial part, the resulting bound states have greater binding energies than those obtained in previous works.