Hidden charm-bottom structures bcb‾c‾: Axial-vector case

Abstract

Mass and width of a hidden charm-bottom axial-vector structure T containing $bc\bar{b}\bar{c}$ quarks are calculated in QCD sum rule framework. It is treated as a diquark-antidiquark state built of scalar diquark and axial-vector antidiquark components. The mass of T is computed using the two-point sum rule method. The width of this particle is evaluated by considering eight decay modes: The decays to ${\eta }_{b}J/\psi$, ${\eta }_c\Upsilon \left(1S\right)$, $B_c^{-}{B}_c^{⁎+}$, and $B_c^{+}{B}_c^{⁎-}$ are dissociation processes, in which all initial quarks are distributed between the final-state particles. The decays to DD and BB mesons with appropriate charges and spin-parities are channels generated due to the annihilations of $b\bar{b}$ and $c\bar{c}$ quarks from T. Partial widths for all of these processes are obtained by employing the three-point sum rule approach necessary to find the strong couplings at relevant tetraquark-meson-meson vertices. Our results for the mass $m=(12715\pm 90)\mathrm{MeV}$ and width $\Gamma \left[T\right]=(140\pm 13)\mathrm{MeV}$ of the tetraquark T, as well as its numerous decay channels explored in this article are useful for ongoing and future experimental investigations of fully heavy resonances.