We study the properties of fully-heavy tetraquarks at finite temperature and their production in high-energy nuclear collisions. We obtain the masses and wave functions of the exotic hadron states $cc\bar c\bar c$ and $bb\bar b\bar b$ by solving the four-body Schrodinger equation in vacuum and strongly interacting matter. In vacuum, the tetraquarks are above the corresponding meson-meson mass threshold, and the newly observed exotic state $X(6900)$ might be a $cc\bar c\bar c$ state with quantum number $J^{PC}=0^{++}$ or $1^{+-}$. In hot medium, the temperature dependence of the tetraquark masses and the dissociation temperatures are calculated. Taking the wave function at finite temperature, we construct the Wigner function for the tetraquark states and calculate, with coalescence mechanism, the production yield and transverse momentum distribution of $cc\bar c\bar c$ in heavy-ion collisions at LHC energy. In comparison with nucleon-nucleon collisions, the yield per binary collision is significantly enhanced.

中文翻译：

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强相互作用介质中的全重四夸克

我们研究了全重四夸克在有限温度下的性质及其在高能核碰撞中的产生。我们通过在真空和强相互作用物质中求解四体薛定谔方程，获得奇异强子态 $cc\bar c\bar c$ 和 $bb\bar b\bar b$ 的质量和波函数。在真空中，四夸克高于相应的介子-介子质量阈值，新观察到的奇异状态 $X(6900)$ 可能是 $cc\bar c\bar c$ 状态，量子数为 $J^{PC}= 0^{++}$ 或 $1^{+-}$。在热介质中，计算四夸克质量和解离温度的温度依赖性。取有限温度下的波函数，我们构造四夸克态的 Wigner 函数并用聚结机制计算，LHC能量重离子碰撞中$cc\bar c\bar c$的产率和横向动量分布。与核子-核子碰撞相比，每次二元碰撞的产率显着提高。