标题： 标准模型真空与矢量型轻子的稳定性：一项批判性考察 显示英文标题

标题： Stability of the Standard Model Vacuum with Vector-Like Leptons: A Critical Examination

摘要： 标准模型（SM）希格斯真空的稳定性是粒子物理中的一个长期问题。 SM希格斯四次耦合参数在高能标下预计会变为负值，可能在达到普朗克尺度之前产生不稳定的真空。 我们研究了在六种不同的规范反常独立表示中引入矢量型轻子（VLLs）是否可以稳定SM真空，而无需引入额外的标量场。 通过分析这些VLLs与SM轻子的质量谱和混合角，我们确定了希格斯势保持稳定的情况。 我们证明存在一组允许但被限制的VLL谱，确实可以稳定SM真空。 我们还研究了这些VLLs对电弱精密观测量的影响，特别是斜率参数S和T，以确保符合全局实验约束。 最后，我们对由电弱精密数据允许的参数空间和稳定所需的参数空间进行了全面分析，突出了同时满足两者的案例。 这项研究为理解矢量型轻子在将标准模型的有效性扩展到普朗克尺度中的作用开辟了新的途径。 显示英文摘要

摘要： The stability of the Standard Model (SM) Higgs vacuum is a long-standing issue in particle physics. The SM Higgs quartic coupling parameter is expected to become negative at high scales, potentially generating an unstable vacuum well before reaching the Planck scale. We investigate whether the introduction of vector-like leptons (VLLs) in six distinct gauge anomaly-independent representations can stabilize the SM vacuum without introducing additional scalar fields. By analyzing the mass spectrum and mixing angles of these VLLs with the SM leptons, we identify conditions under which the Higgs potential remains stable. We demonstrate that there exists a set of allowed but narrowed VLL spectra that can indeed stabilize the SM vacuum. We also study the effect of these VLLs on electroweak precision observables, particularly the oblique parameters S and T to ensure fit within global experimental constraints. Finally, we perform a comprehensive analysis of the parameter space allowed by electroweak precision data and the parameter space required for stability, highlighting cases that accommodate both. This study opens up new avenues for understanding the role of vector-like leptons in extending the validity of the Standard Model up to the Planck scale.