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

The D(∗)Ξcc(∗) system and Ξ¯cc(∗)Ξcc(∗) 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++D¯∗D∗ 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∗Ξcc and JP=5/2-D∗Ξcc∗. In the baryon-baryon system, there exist seven di-baryon molecules, JPC=0-+Ξ¯ccΞcc, JPC=1--Ξ¯ccΞcc, JPC=1-+Ξ¯ccΞcc∗, JPC=1--Ξ¯ccΞcc∗, JPC=2-+Ξ¯ccΞcc∗, JPC=2-+Ξ¯cc∗Ξcc∗, and JPC=3--Ξ¯cc∗Ξcc∗. Among them, the JPC=0-+Ξ¯ccΞcc 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¯(∗)Ξbb(∗), and Ξ¯bb(∗)Ξbb(∗) systems.