We update lattice QCD results for second order cumulants of conserved charge fluctuations and correlations at nonzero temperature and vanishing values of the conserved charge chemical potentials. We compare these results to hadron resonance gas calculations with and without excluded volume terms as well as S-matrix results in the hadronic phase of QCD and comment on their current limitations. We, furthermore, use these results to characterize thermal conditions in the vicinity of the pseudocritical line of the chiral transition in QCD. We argue that the ratio of strange to baryon chemical potentials is a robust observable that, on the one hand, deviates only little from hadron resonance gas results, but, on the other hand, is very sensitive to the spectrum of strange baryon resonances.

中文翻译：

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重新审视守恒电荷波动的二阶累积量：消失的化学势

我们更新了非零温度下守恒电荷波动和相关性的二阶累积量的晶格 QCD 结果以及守恒电荷化学势的消失值。我们将这些结果与具有和不具有排除体积项的强子共振气体计算以及 QCD 强子相中的 S 矩阵结果进行比较，并评论它们当前的局限性。此外，我们使用这些结果来表征 QCD 中手性转变的伪临界线附近的热条件。我们认为，奇异重子化学势的比率是一个可靠的观测值，一方面，它与强子共振气体结果的偏差很小，但另一方面，它对奇异重子共振的光谱非常敏感。