Abstract We perform a comprehensive study of collider aspects of a Higgs portal scenario that is protected by an unbroken Z 2 symmetry. If the mass of the Higgs portal scalar is larger than half the Higgs mass, this scenario becomes very difficult to detect. We provide a detailed investigation of the model's parameter space based on analyses of the direct collider sensitivity at the LHC as well as at future lepton and hadron collider concepts and analyse the importance of these searches for this scenario in the context of expected precision Higgs and electroweak measurements. In particular we also consider the associated electroweak oblique corrections that we obtain in a first dedicated two-loop calculation for comparisons with the potential of, e.g., GigaZ. The currently available collider projections corroborate an FCC-hh 100 TeV as a very sensitive tool to search for such a weakly-coupled Higgs sector extension, driven by small statistical uncertainties over a large range of energy coverage. Crucially, however, this requires good theoretical control. Alternatively, Higgs signal-strength measurements at an optimal FCC-ee sensitivity level could yield comparable constraints.

中文翻译：

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Power 遇到 Precision 探索对称希格斯门户

摘要 我们对受完整 Z 2 对称性保护的 Higgs 门户场景的对撞机方面进行了全面研究。如果希格斯门户标量的质量大于希格斯质量的一半，这种情况就很难被发现。我们基于对 LHC 直接对撞机灵敏度的分析以及未来轻子和强子对撞机概念的分析，对模型的参数空间进行了详细调查，并分析了这些搜索在预期精度希格斯和电弱的背景下对这种情况的重要性测量。特别地，我们还考虑了我们在第一次专用双回路计算中获得的相关电弱倾斜校正，以与 GigaZ 等电位进行比较。当前可用的对撞机预测证实了 FCC-hh 100 TeV 作为一种非常敏感的工具来搜索这种弱耦合的希格斯扇区扩展，这是由大范围能量覆盖范围内的小统计不确定性驱动的。然而，至关重要的是，这需要良好的理论控制。或者，在最佳 FCC-ee 灵敏度水平下进行 Higgs 信号强度测量可能会产生类似的限制。