Heavy scalar molecule $B_c^{+}{B}_c^{-}$

Abstract

Mass and full width of the heavy scalar molecule $\mathcal{M}$ composed of the mesons $B_c^{+}$ and $B_c^{-}$ are calculated in the QCD sum rule framework. To find its mass and current coupling, we apply the two-point sum rule method. The width of the hadronic molecule $\mathcal{M}=B_c^{+}{B}_c^{-}$ is evaluated by taking into account its dissociation to $\hat{I}{\cdot }_c\hat{I}{\cdot }_b,J/\ddot{I}ˆ\hat{I}\yen$, and $B_c^{+}{B}_c^{-}$ mesons. Decays into $D$ and $B$ meson pairs with appropriate charges and quantum numbers triggered by $\overline{b}b$ and $\overline{c}c$ annihilations to light quark-antiquarks are also included in the analyses. Because the partial widths of $\mathcal{M}$ molecule's decay channels depend on the strong couplings at $\mathcal{M}$-meson-meson vertices, we estimate them by invoking tools of the three-point sum rule method. Our predictions $m=(12725\pm 85)\mathrm{MeV}$ and $\hat{I}“[\mathcal{M}]=(155\pm 23)\mathrm{MeV}$ for the parameters of the molecule $\mathcal{M}$ provide useful information for experimental studies of numerous heavy resonances.

12 Pages, 4 Figures and 1 Table