Doubly Heavy Tetraquark Multiplets As Heavy Antiquark-Diquark Symmetry Partners of Heavy Baryons

Symmetries play important roles in the understanding of hadron structures and spectroscopy. Motivated by the discovery of the doubly charmed tetraquark T-cc(+)(3875), we study the ground states of the doubly heavy tetraquarks with the QCD inspired heavy antiquark-diquark symmetry in the constituent quark model. Six ground states of T-QQ(Q = c, b) are predicted and the lightest T-cc state has a mass of 3875.8 +/- 7.6 MeV and spin-parity 1(+), which are consistent with those of the observed T-cc(+)(3875). In addition, the magnetic moments of the predicted tetraquarks T-cc(+)(3875) and T-bb(-)(10396) are also estimated in the same model, which provide further information to distinguish the structures of the T-QQ states.