Relativistic description of asymmetric fully heavy tetraquarks in the diquark-antidiquark model

Masses of the ground, orbitally and radially excited states of the asymmetric fully heavy tetraquarks, composed of charm © and bottom (b) quarks and antiquarks are calculated in the relativistic diquark-antidiquark picture. The relativistic quark model based on the quasipotential approach and quantum chromodynamics is used to construct the quasipotentials of the quark-quark and diquark-antidiquark interactions. These quasipotentials consist of the short-range one-gluon exchange and long-distance linear confinement interactions. Relativistic effects are consistently taken into account. A tetraquark is considered as a bound state of a diquark and an antidiquark which are treated as a spatially extended colored objects and interact as a whole. It is shown that most of the investigated tetraquarks states (including all ground states) lie above the fall-apart strong decay thresholds into a meson pair. As a result they can be observed as wide resonances. Nevertheless, several orbitally excited states lie slightly above or even below these fall-apart thresholds, thus they could be narrow states.