Decays of fully beauty scalar tetraquarks to ${B}_{q}{\overline{B}}_{q}$ and ${B}_{q}^{*}{\overline{B}}_{q}^{*}$ mesons

Decays of the fully beauty four-quark structures ${X}_{4b}$ and ${T}_{4b}$ to $B$ meson pairs are investigated in the framework of the QCD three-point sum rule method. We model the scalar exotic mesons ${X}_{4b}$ and ${T}_{4b}$ as diquark-antidiquark systems composed of the axial-vector and pseudoscalar diquarks, respectively. The masses $m=\left(18540±50\right)\text{}\text{}\mathrm{MeV}$ and $\stackrel{˜}{m}=\left(18858±50\right)\text{}\text{}\mathrm{MeV}$ of these compounds calculated in our previous articles fix possible decay channels of these particles. In the present work, we consider their decays to ${B}_{q}{\overline{B}}_{q}$ and ${B}_{q}^{*}{\overline{B}}_{q}^{*}$ ($q=u$, $d$, $s$, $c$) mesons. In the case of ${X}_{4b}$, the mass of which is below the $2{\eta }_{b}$ threshold, these channels determine essential part of its full width ${\Gamma }_{4b}$. The tetraquark ${T}_{4b}$ can decay to the pair ${\eta }_{b}{\eta }_{b}$; therefore, partial widths of processes with $B\left({B}^{*}\right)$ mesons in the final state permit us to refine our estimate for the full width of this particle. The predictions ${\Gamma }_{4b}=\left(9.6±1.1\right)\text{}\text{}\mathrm{MeV}$ and ${\stackrel{˜}{\Gamma }}_{4b}^{\text{Full}}=\left(144±29\right)\text{}\text{}\mathrm{MeV}$ obtained in this article can be used in future experimental investigations of four $b$-quark mesons.