Holographic tetraquarks and the newly observed T-cc(+) at LHCb

We describe a heavy and exotic tetraquark state as a holographic molecule, by binding the lightest heavylight meson (0-, 1-) multiplet to a flavored sphaleron, in the bulk of the Witten-Sakai-Sugimoto model. Bound tetraquark states emerge as Efimov states in the heavy quark limit, with a binding energy for a charm tetraquark comparable to the T thorn cc recently reported by the LHCb collaboration, but with a substantially smaller width, for a large but finite 't Hooft coupling. Fixing the parameters of the model at the empirical mass of T thorn cc, allows for a prediction of the bindings of the undiscovered bottom-charm and bottom tetraquarks.