We review the recent status of the QCD sum rule approach to study the properties of hadrons in vacuum and in hot or dense matter. Special focus is laid on the progress made in the evaluation of the QCD condensates, which are the input of all QCD sum rule calculations, and for which much new information has become available through high precision lattice QCD calculations, chiral perturbation theory and experimental measurements. Furthermore, we critically examine common analysis methods for QCD sum rules and contrast them with potential alternative strategies. The status of QCD sum rule studies investigating the modification of hadrons at finite density as well as recent derivations of exact sum rules applicable to finite temperature spectral functions, are also reviewed.

中文翻译：

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QCD凝析油评价及求和规则的最新进展

我们回顾了 QCD 总和规则方法的最新状态，用于研究真空和热或致密物质中强子的特性。特别关注 QCD 凝聚物的评估取得的进展，这是所有 QCD 和规则计算的输入，并且通过高精度晶格 QCD 计算、手性微扰理论和实验测量获得了许多新信息。此外，我们批判性地检查了 QCD 总和规则的常见分析方法，并将它们与潜在的替代策略进行了对比。还回顾了研究有限密度下强子修正的 QCD 求和规则研究的现状以及适用于有限温度谱函数的精确求和规则的最新推导。