Analysis of $DD^*$ and $\bar{D}^{(*)}\Xi_{cc}^{(*)}$ molecule by one boson exchange model based on Heavy quark symmetry

TL;DR

This paper investigates the potential existence of a $ar{D}\Xi_{cc}$ molecular state using a one boson exchange model, guided by heavy quark symmetry, predicting a bound state that could shed light on the nature of the $T_{cc}$ tetraquark.

Contribution

The study applies a one boson exchange model respecting heavy quark symmetry to predict a new $ar{D}^{(*)}\Xi_{cc}^{(*)}$ bound state based on superflavor symmetry, extending previous tetraquark analyses.

Findings

Predicted a $ar{D}\Xi_{cc}$ bound state with $I(J^P)=0(rac{1}{2}^-)$.

Model reproduces the $T_{cc}$ binding energy, supporting the molecular interpretation.

Supports the hypothesis that $T_{cc}$ is a $DD^*$ molecular state.

Abstract

Numerous exotic hadrons with heavy quarks have been reported in the experiments. In such states, symmetries of heavy quarks are considered to play a significant role. In particular, the superflavor symmetry, or also called the heavy quark anti-diquark symmetry is one of the interesting symmetries, which links a quark $Q$ to an anti-diquark $\bar{Q}\bar{Q}$ having the same color representation as $Q$. In this paper, we study a $\bar{D}\Xi_{cc}$ molecular state as a superflavor partner of the doubly charm tetraquark $T_{cc}$ reported by LHCb recently. $T_{cc}$ locating slightly below the $DD^*$ threshold is a candidate of the hadronic molecule. Thus by replacing the singly charm meson $D^{(*)}$ with the doubly charm baryon $\Xi_{cc}^{(*)}$, superflavor symmetry predicts the existence of the $\bar{D}^{(*)}\Xi_{cc}^{(*)}$ bound state. We employ the one boson exchange model respecting with the heavy quark spin symmetry where the parameter is obtained to reproduce the $T_{cc}$ binding energy. We apply this model with superflavor symmetry to the $\bar{D}^{(*)}\Xi_{cc}^{(*)}$ molecule and predict a bound state with $I(J^P) = 0(\frac{1}{2}^-)$. If the pentaquark state corresponding to $\bar{D}^{(*)} \Xi_{cc}^{(*)}$ molecular state is observed in future experiments as predicted in this work, it is more likely that $T_{cc}$ is a $DD^*$ molecular state.