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

Abstract

AbstractThe $$D^{(*)}\Xi _{cc}^{(*)}$$ D ( ∗ ) Ξ cc ( ∗ ) system and $${\bar{\Xi }}_{cc}^{(*)}\Xi _{cc}^{(*)}$$ Ξ ¯ cc ( ∗ ) Ξ cc ( ∗ ) system can be related to the $$D^{(*)}{\bar{D}}^{(*)}$$ 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 $$1^{++}~D{\bar{D}}^{*}$$ 1 + + D D ¯ ∗ 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 $$J^{PC}=2^{++}~{\bar{D}}^{*}D^{*}$$ J PC = 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, $$J^{P}=1/2^{-}~D^{*}\Xi _{cc}$$ J P = 1 / 2 - D ∗ Ξ cc and $$J^{P}=5/2^{-}~D^{*}\Xi _{cc}^{*}$$ J P = 5 / 2 - D ∗ Ξ cc ∗ . In the baryon-baryon system, there exist seven di-baryon molecules, $$J^{PC}=0^{-+}~{\bar{\Xi }}_{cc}\Xi _{cc}$$ J PC = 0 - + Ξ ¯ cc Ξ cc , $$J^{PC}=1^{--}~{\bar{\Xi }}_{cc}\Xi _{cc}$$ J PC = 1 - - Ξ ¯ cc Ξ cc , $$J^{PC}=1^{-+}~{\bar{\Xi }}_{cc}\Xi _{cc}^{*}$$ J PC = 1 - + Ξ ¯ cc Ξ cc ∗ , $$J^{PC}=1^{--}~{\bar{\Xi }}_{cc}\Xi _{cc}^{*}$$ J PC = 1 - - Ξ ¯ cc Ξ cc ∗ , $$J^{PC}=2^{-+}~{\bar{\Xi }}_{cc}\Xi _{cc}^{*}$$ J PC = 2 - + Ξ ¯ cc Ξ cc ∗ , $$J^{PC}=2^{-+}~{\bar{\Xi }}_{cc}^{*}\Xi _{cc}^{*}$$ J PC = 2 - + Ξ ¯ cc ∗ Ξ cc ∗ , and $$J^{PC}=3^{--}~{\bar{\Xi }}_{cc}^{*}\Xi _{cc}^{*}$$ J PC = 3 - - Ξ ¯ cc ∗ Ξ cc ∗ . Among them, the $$J^{PC}=0^{-+}~{\bar{\Xi }}_{cc}\Xi _{cc}$$ J PC = 0 - + Ξ ¯ cc Ξ 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 $$B^{(*)}{\bar{B}}^{(*)}$$ B ( ∗ ) B ¯ ( ∗ ) , $${\bar{B}}^{(*)}\Xi _{bb}^{(*)}$$ B ¯ ( ∗ ) Ξ bb ( ∗ ) , and $${\bar{\Xi }}_{bb}^{(*)}\Xi _{bb}^{(*)}$$ Ξ ¯ bb ( ∗ ) Ξ bb ( ∗ ) systems.