Parameters of the tensor tetraquark $bb\overline{c}\overline{c}$

Abstract

The mass and width of the tensor tetraquark $T=bb\overline{c}\overline{c}$ with spin-parity $J^{\mathrm{P}}=2^{+}$ are calculated in the context of the QCD sum rule method. The tetraquark $T$ is modeled as a diquark-antidiquark state built of components $b^{T}C{\gamma }_{\mu }b$ and $\overline{c}{\gamma }_{\nu }C{\overline{c}}^T$ with $C$ being the charge conjugation matrix. The mass $m=(12.795\pm 0.095)\mathrm{GeV}$ of the exotic tensor meson $T$ is found by means of the two-point sum rule approach. Its full width $\Gamma$ is evaluated by considering processes $T\to B_c^{-}{B}_c^{-}$, $B_c^{-}{B}_c^{\ast -}$, and $B_c^{\ast -}{B}_c^{\ast -}$. Partial widths of these decays are computed by means of the three-point sum rule approach which is used to determine the strong couplings at relevant tetraquark-meson-meson vertices. Predictions obtained for the width ${\Gamma }_{\mathrm{T}}=55.5_{-9.9}^{+10.6}\mathrm{MeV}$, as well as the mass of the tetraquark $T$ can be useful in investigations of fully heavy four-quark mesons.

Comments: 9 Pages and 5 Figures