Excited states of triply heavy tetraquarks

Masses of ground and radially and orbitally excited states of triply heavy tetraquarks with a pair of open and hidden heavy flavors (charm, bottom) were calculated within the relativistic quark model, based on the quasipotential approach and QCD. A tetraquark is considered as a bound state of a diquark with an antidiquark. Diquarks are treated as color--triplet states. Calculations take into account all relativistic effects (spin--independent and spin--dependent) and finite size of diquarks. Obtained results are compared with the strong fall--apart decay thresholds into a pair of heavy and heavy--light mesons. Tetraquark states that are most promising candidates for experimental searches are identified.