For very heavy quarks $Q$, relations derived from heavy-quark symmetry predict the existence of novel narrow doubly heavy tetraquark states of the form $Q_i{Q}_j{\overline{q}}_k{\overline{q}}_l$ (subscripts label flavors), where $q$ designates a light quark. By evaluating finite-mass corrections, we predict that double-beauty states composed of $bb\overline{u}\overline{d}$, $bb\overline{u}\overline{s}$, and $bb\overline{d}\overline{s}$ will be stable against strong decays, whereas the double-charm states $cc{\overline{q}}_k{\overline{q}}_l$, mixed $\mathrm{beauty}+\mathrm{charm}$ states $bc{\overline{q}}_k{\overline{q}}_l$, and heavier $bb{\overline{q}}_k{\overline{q}}_l$ states will dissociate into pairs of heavy-light mesons. Observation of a new double-beauty state through its weak decays would establish the existence of tetraquarks and illuminate the role of heavy color-antitriplet diquarks as hadron constituents.

中文翻译：

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重夸克对称性表示稳定的重四夸克介子

对于非常重的夸克 $问$源自重夸克对称性的关系预示了形式的新型窄双重四夸克态的存在 ${问}_{\mathrm{一世}}{问}_{Ĵ}{\overline{q}}_{ķ}{\overline{q}}_{升}$ （下标标签的口味），其中 $q$指定一个轻夸克。通过评估有限质量修正，我们可以预测由$bb\overline{ü}\overline{d}$， $bb\overline{ü}\overline{s}$， 和 $bb\overline{d}\overline{s}$ 对抗强衰变会保持稳定，而双魅力状态 $CC{\overline{q}}_{ķ}{\overline{q}}_{升}$，混合 $\mathrm{美丽}+\mathrm{魅力}$ 状态 $bC{\overline{q}}_{ķ}{\overline{q}}_{升}$而且较重 $bb{\overline{q}}_{ķ}{\overline{q}}_{升}$各州将分解为成对的轻介子。通过其弱衰变观察新的双美态将建立四夸克的存在，并阐明重色-三重双色夸克作为强子成分的作用。