Axial-vector molecular structures $B_{c}^{\ast \pm} B_{c}^{\mp}$

TL;DR

This paper investigates the properties of an axial-vector molecular state composed of Bc mesons using QCD sum rules, predicting its mass, decay widths, and potential decay channels for experimental detection.

Contribution

It provides the first QCD sum rule analysis of the axial-vector Bc meson molecule, calculating its mass, decay widths, and strong couplings, offering predictions for experimental searches.

Findings

Mass of the molecule: (12770 ± 60) MeV

Full decay width: (93 ± 14) MeV

Identifies dominant decay channels

Abstract

The axial-vector molecular structure $\mathcal{M}_{\mathrm{AV}}=(B_{c}^{\ast +}B_{c}^{-} + B_{c}^{\ast - } B_{c}^{+})/2$ is explored in QCD sum rule framework. The mass and current coupling of this compound are found by means of the two-point sum rule method. It turns out that the mass of $\mathcal{M} _{\mathrm{AV}}$ is equal to $m=(12770 \pm 60)~\mathrm{MeV}$ making possible its dissociations to pairs of $J/\psi \eta_b$, $\Upsilon \eta_c$, $ B_{c}^{\ast +} B_{c}^{-}$, and $B_{c}^{\ast - } B_{c}^{+}$ mesons. The partial widths of these decay modes contain the strong couplings at $ \mathcal{M}_{\mathrm{AV}}$-meson-meson vertices which are calculated by utilizing the three-point sum rule method. The full decay width of the molecule $\mathcal{M}_{\mathrm{AV}}$ is formed due to these dominant processes and amounts to $\Gamma[\mathcal{M}_{\mathrm{AV}}]=(93 \pm 14)~ \mathrm{MeV}$. Our results for parameters $m$ and $\Gamma[\mathcal{M}_{ \mathrm{AV}}]$ of the hadronic molecule $\mathcal{M}_{\mathrm{AV}}$ are useful for experimental studies of various fully heavy four-quark mesons.