Bell tests have become a powerful tool for quantifying security, randomness, entanglement, and many other properties, as well as for investigating fundamental physical limits. In all these cases, the specific experimental value of the Bell parameter is important as it leads to a quantitative conclusion. However, experimental implementations can also produce experimental data with (apparent) signaling. This signaling can be attributed to systematic errors occurring due to weaknesses in the experimental designs. Here we point out the importance, for quantitative applications, to identify and address this problem. We present a set of experiments with polarization-entangled photons in which we identify common sources of systematic errors and demonstrate approaches to avoid them. In addition, we establish the highest experimental value for the Bell-CHSH parameter obtained after applying strategies to minimize signaling that we are aware of: $S = 2.812 \pm 0.003$ and negligible systematic errors. The experiments did not randomize the settings and did not close the locality loophole.

中文翻译：

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如何在 Bell 测试中避免（明显）信令

贝尔测试已成为量化安全性、随机性、纠缠和许多其他属性以及研究基本物理极限的强大工具。在所有这些情况下，贝尔参数的特定实验值都很重要，因为它会导致定量结论。但是，实验实现也可以生成具有 （明显） 信号的实验数据。这种信号转导可归因于由于实验设计中的弱点而发生的系统误差。在这里，我们指出了定量应用识别和解决这个问题的重要性。我们提出了一组偏振纠缠光子的实验，在这些实验中，我们确定了系统误差的常见来源并演示了避免它们的方法。此外，我们为应用策略以最小化我们所知道的信号传导后获得的 Bell-CHSH 参数建立了最高实验值：$S = 2.812 \pm 0.003$ 和可忽略不计的系统误差。实验没有随机化设置，也没有填补局部漏洞。