We use lattice QCD to investigate the existence of strong-interaction-stable antiheavy-antiheavy-light-light tetraquarks. We study the $\overline{b}\overline{b}us$ system with quantum numbers $J^P=1^{+}$ as well as the $\overline{b}\overline{c}ud$ systems with quantum numbers $I(J^P)=0(0^{+})$ and $I(J^P)=0(1^{+})$. We carry out computations on five gauge-link ensembles with $2+1$ flavors of domain-wall fermions, including one at the physical pion mass. The bottom quarks are implemented using lattice nonrelativistic QCD, and the charm quarks using an anisotropic clover action. In addition to local diquark-antidiquark and local meson-meson interpolating operators, we include nonlocal meson-meson operators at the sink, which facilitates the reliable determination of the low-lying energy levels. We find clear evidence for the existence of a strong-interaction-stable $\overline{b}\overline{b}us$ tetraquark with binding energy $(-86\pm 22\pm 10)\mathrm{MeV}$ and mass $(10609\pm 22\pm 10)\mathrm{MeV}$. For the $\overline{b}\overline{c}ud$ systems we do not find any indication for the existence of bound states, but cannot rule out their existence either.

中文翻译：

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使用晶格 QCD 搜索 b¯b¯usandb¯c¯udtetraquark 束缚态

我们使用晶格QCD来研究强相互作用稳定的反重反重轻轻四夸克的存在。我们研究$\overline{b}\overline{b}你s$具有量子数的系统${Ĵ}^{磷}=1^{+}$以及$\overline{b}\overline{C}你d$具有量子数的系统$我({Ĵ}^{磷})=0(0^{+})$和$我({Ĵ}^{磷})=0(1^{+})$. 我们对五个规范链接集合进行计算$2+1$畴壁费米子的味道，包括物理π介子质量的一种。底夸克使用晶格非相对论 QCD 实现，而粲夸克使用各向异性三叶草作用。除了局部二夸克-反二夸克和局部介子-介子插值算子外，我们还包括汇处的非局部介子-介子算子，这有助于可靠地确定低能级。我们找到了存在强相互作用稳定的明确证据$\overline{b}\overline{b}你s$具有结合能的四夸克$(-86\pm 22\pm 10)\mathrm{电子伏特}$和质量$(10609\pm 22\pm 10)\mathrm{电子伏特}$. 为了$\overline{b}\overline{C}你d$我们没有发现任何束缚态存在的迹象，但也不能排除它们的存在。