Heavy four-quark mesons : Scalar particle

Parameters of the heavy four-quark scalar meson ${T}_{\mathrm{bc}\stackrel{‾}{b}\stackrel{‾}{c}}$ with content $bc\stackrel{‾}{b}\stackrel{‾}{c}$ are calculated by means of the sum rule method. This structure is considered as a diquark-antidiquark state built of scalar diquark and antidiquark components. The mass and current coupling of ${T}_{\mathrm{bc}\stackrel{‾}{b}\stackrel{‾}{c}}$ are evaluated in the context of the two-point sum rule approach. The full width of this tetraquark is estimated by taking into account two types of its possible strong decay channels. First class includes dissociation of ${T}_{\mathrm{bc}\stackrel{‾}{b}\stackrel{‾}{c}}$ to mesons ${\eta }_{c}{\eta }_{b}$, ${B}_{c}^{+}{B}_{c}^{-}$, ${B}_{c}^{⁎+}{B}_{c}^{⁎-}$ and ${B}_{c}^{+}\left({1}^{3}{P}_{0}\right){B}_{c}^{⁎-}$. Another type of processes are generated by annihilations $\stackrel{‾}{b}b\to \stackrel{‾}{q}q$ of constituent b-quarks which produces the final-state charmed meson pairs ${D}^{+}{D}^{-}$, ${D}^{0}{\stackrel{‾}{D}}^{0}$, ${D}^{⁎+}{D}^{⁎-}$, and ${D}^{⁎0}{\stackrel{‾}{D}}^{⁎0}$. Partial width all of these decays are found using the three-point sum rule method which is required to calculate strong couplings at corresponding meson-meson-tetraquark vertices. Predictions obtained for the mass $m=\left(12697±90\right)\phantom{\rule{0.25em}{0ex}}\mathrm{MeV}$ and width $\Gamma \left[{T}_{\mathrm{bc}\stackrel{‾}{b}\stackrel{‾}{c}}\right]=\left(142.4±16.9\right)\phantom{\rule{0.25em}{0ex}}\mathrm{MeV}$ of this state are compared with alternative results, and are useful for further experimental investigations of fully heavy resonances.