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 heavy-light 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 charm tetraquark comparable to the $T_{cc}^+$ recently reported by the LHCb, but a substantially smaller width, for a large but finite $^\prime$t Hooft coupling. Fixing the parameters of the model at the empirical mass of $T_{cc}^+$ allows us to predict the bindings of the undiscovered so far bottom-charm and bottom tetraquarks, when interpreted as Efimov states.