A family of double-beauty tetraquarks: Axial-vector state $T_{bb;\bar{u}\bar{s}}^{-}$

The spectroscopic parameters and decay channels of the axial-vector tetraquark $T_{bb;\bar{u}\bar{s}}^{-}$ (in what follows, $T_{b: \overline{s}}^{$\mathrm{A}\mathrm{V}$}$) are explored using the quantum chromodynamics (QCD) sum rule method. The mass and coupling of this state are calculated using two-point sum rules by taking into account various vacuum condensates, up to 10 dimensions. Our prediction for the mass of this state $m=(10215\pm 250)~ $\mathrm{M}\mathrm{e}\mathrm{V}$$ confirms that it is stable with respect to strong and electromagnetic decays and can dissociate to conventional mesons only via weak transformations. We investigate the dominant semileptonic $T_{b:\overline{s} }^{$\mathrm{A}\mathrm{V}$} \to $\mathcal{Z}${b:\overline{s}}^{0}l\overline{\nu}l$ and nonleptonic $T{b:\overline{s}}^{$\mathrm{A}\mathrm{V}$} \to $\mathcal{Z}${b:\overline{s} }^{0}M$decaysof$T_{b:\overline{s}}^{$\mathrm{A}\mathrm{V}$}$\mathrm{.}Intheseprocesses,$ $\mathcal{Z}${b:\overline{s}}^{0}$isascalartetraquark$[bc][\overline{u} \overline{s}]$builtofacolor-tripletdiquarkandanantidiquark,whereas$M$isoneofthevectormesons$\rho ^{-}$,$K^{\ast}(892)$,$D^{\ast }(2010)^{-}$,and$D{s}^{\ast -}$. To calculate the partial widths of these decays, we use the QCD three-point sum rule approach and evaluate the weak transition form factors $G_i$ $(i=0,1,2,3)$, which govern these processes. The full width $\Gamma {$\mathrm{f}\mathrm{u}\mathrm{l}\mathrm{l}$} =(12.9\pm 2.1)\times 10^{-8}~$\mathrm{M}\mathrm{e}\mathrm{V}$$andthemeanlifetime$ \tau=5.1{-0.71}^{+0.99}~$\mathrm{f}\mathrm{s}$$ofthetetraquark$T_{b:\overline{s}}^{ $\mathrm{A}\mathrm{V}$}$ are computed using the aforementioned weak decays. The obtained information about the parameters of $T_{b:\bar{s}}^{\mathrm{A}\mathrm{V}}$ and ${\mathcal{Z}}_{b:\bar{s}}^0$ is useful for experimental investigations of these double-heavy exotic mesons.