Is X(7200) the heavy anti-quark diquark symmetry partner of X(3872)?

The D()Xi cc() system and Xi cc()Xi cc() system can be related to the D()D() system via heavy anti-quark di-quark symmetry (HADS). In this work, we employ a contact-range effective field theory to systematically investigate the likely existence of molecules in these systems in terms of the hypothesis that X(3872) is a 1++DD bound state in the isospin symmetry limit, with some of the unknown low energy constants estimated using the light-meson saturation approximation. In the meson-meson system, a JPC=2++DD molecule commonly referred to as X(4013) is reproduced, which is the heavy quark spin partner of X(3872). In the meson-baryon system, we predict two triply charmed pentaquark molecules, JP=1/2-D Xi cc and JP=5/2-D Xi cc. In the baryon-baryon system, there exist seven di-baryon molecules, JPC=0-+Xi cc Xi cc, JPC=1--Xi cc Xi cc, JPC=1-+Xi cc Xi cc, JPC=1--Xi cc Xi cc, JPC=2-+Xi cc Xi cc, JPC=2-+Xi cc Xi cc, and JPC=3--Xi cc Xi cc. Among them, the JPC=0-+Xi ccXi cc molecule may contribute to the X(7200) state recently observed by the LHCb Collaboration, which implies that X(7200) can be related to X(3872) via HADS. As a byproduct, with the heavy quark flavor symmetry we also study likely existence of molecular states in the B()B(), B()Xi bb(), and Xi bb()Xi bb() systems.

Automated summary

This study investigates the possible existence of molecules in systems such as D()Xi cc(), Xi cc()Xi cc(), B()B(), B()Xi bb(), and Xi bb()Xi bb() using heavy anti-quark di-quark symmetry. Through the analysis, various molecular states are predicted in different systems, with the implication that X(7200) may be related to X(3872) in some way.