Masses of doubly heavy tetraquarks TQQ′ in a relativized quark model

In the present work, the mass spectra of doubly heavy tetraquarks T-QQ' are systematically investigated in a relativized quark model. The four-body systems including the Coulomb potential, confining potential, spin-spin interactions, and relativistic corrections are solved within the variational method. Our results suggest that the IJ(P) = 01+ bb (u) over tilde(d) over bar state is 54 MeV below the relevant (B) over bar(B) over bar* thresholds, which indicates that both strong and electromagnetic decays are forbidden, and thus this state can be a stable one. Its large hidden color component and small root mean square radius demonstrate that it is a compact tetraquark rather than a loosely bound molecule or pointlike diquark-antidiquark structure. Our predictions of the doubly heavy tetraquarks may provide valuable information for future experimental searches.