Hidden charm-bottom structures $bc\overline{b}\overline{c}$: Axial-vector case

Abstract

Mass and width of a hidden charm-bottom axial-vector structure $T$ containing $bc\overline{b}\overline{c}$ 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 ${\eta }_{b}J/\psi$, ${\eta }_c{\rm Y}(1S)$, $B_c^{-}{B}_c^{\ast +}$, and $B_c^{+}{B}_c^{\ast -}$ 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 $b\overline{b}$ and $c\overline{c}$ 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 $\Gamma [T]=(140\pm 13)\mathrm{MeV}$ 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.

Comments: 12 Pages and 5 Figures