Prediction of an $I(J^P)=0(1^{-})$ $\bar{b}\bar{b}ud$ Tetraquark Resonance Close to the $B^{\ast }{B}^{\ast }$ Threshold Using Lattice QCD Potentials

Abstract

We use antistatic-antistatic potentials computed with lattice QCD and a coupled-channel Born-Oppenheimer approach to explore the existence of a $\bar{b}\bar{b}ud$ tetraquark resonance with quantum numbers $I(J^P)=0(1^{-})$. A pole in the $\text{mbox}T$ matrix signals a resonance with mass $m=2m_B+94.0_{-5.4}^{+1.3}\text{MeV}$ and decay width $\Gamma =140_{-66}^{+86}\text{MeV}$, i.e. very close to the $B^{\ast }{B}^{\ast }$ threshold. We also compute branching ratios, which clearly indicate that this resonance is mainly composed of a $B^{\ast }{B}^{\ast }$ meson pair with a significantly smaller $BB$ contribution. By varying the potential matrix responsible for the coupling of the $BB$ and the $B^{\ast }{B}^{\ast }$ channel as well as the $b$ quark mass, we provide additional insights and understanding concerning the formation and existence of the resonance. We also comment on the importance of our findings and the main takeaways for a possible future full lattice QCD investigation of this $I(J^P)=0(1^{-})$ $\bar{b}\bar{b}ud$ tetraquark resonance.

Comments: 20 pages, 6 figures