The Standard model as a low-energy effective theory: what is triggering the Higgs mechanism?
Fred Jegerlehner
备注：
27 pages, 9 figures. Replacement 29 pages, 11 figures, added references, corrected typos, added two additional figures with comments, results unchanged. Fig.6 and Fig.7 and Tab. 1 added Eq. (2) corrected, updated Higgs mass adopted, more details on inflation, finite temperature effects and the cosmological constant are given, notation adjusted
在大型强子对撞机上由ATLAS和CMS发现的希格斯粒子不仅为电弱标准模型提供了最后一块缺失的基石，而且希格斯粒子的质量被发现具有一个非常特殊的值，大约为126 GeV，这使得真空稳定性扩展到普朗克尺度。这可能比迄今为止预期的有更深的缺点。最近有几篇文章讨论了对SM规范、汤川和希格斯耦合（直至普朗克尺度）运行的影响。在这里，我们考虑对运行质量的影响，并讨论二次发散在标准模型中的作用。在μ_0 ~ 1.4 x 10^16 GeV处出现的二次发散项系数的符号变化可以被理解为一级相变，它恢复了对称相，而在较低尺度下它的大负值则触发了希格斯机制，运行参数的演变使得对称性在普朗克尺度之前恢复了两个数量级。因此，电弱相变发生在μ_0尺度，而不是在电弱尺度v ~ 250 GeV。SM希格斯系统及其相变可能对早期宇宙的膨胀起着关键作用。此外，在微扰论令人惊讶地达到普朗克尺度的情况下，重子生成也必须重新考虑。
英文摘要：
The discovery of the Higgs by ATLAS and CMS at the LHC not only provided the last missing building block of the electroweak Standard Model, the mass of the Higgs has been found to have a very peculiar value about 126 GeV, which is such that vacuum stability is extending up to the Planck scale. This may have much deeper drawback than anticipated so far. The impact on the running of the SM gauge, Yukawa and Higgs couplings up to the Planck scale has been discussed in several articles recently. Here we consider the impact on the running masses and we discuss the role of quadratic divergences within the Standard Model. The change of sign of the coefficient of the quadratically divergent terms showing up at about mu_0 ~ 1.4 x 10^16 GeV may be understood as a first order phase transition restoring the symmetric phase, while its large negative values at lower scales triggers the Higgs mechanism, running parameters evolve in such a way that the symmetry is restored two orders of magnitude before the Planck scale. Thus, the electroweak phase transition takes place at the scale mu_0 and not at the electroweak scale v ~ 250 GeV. The SM Higgs system and its phase transition could play a key role for the inflation of the early universe. Also baryogenesis has to be reconsidered under the aspect that perturbative arguments surprisingly work up to the Planck scale.
The charged current production of long-lived heavy neutrinos at the LHC can use a prompt charged lepton for triggering the measurement of the process. However, in order to fully characterize the heavy neutrino interactions, it is necessary to also probe Higgs or $Z$ mediated neutral current production. In this case the charged lepton is not available, so other means of triggering are required. In this work, we explore the possibility of using a vector boson fusion trigger in the context of a GeV-scale Type I Seesaw model. We consider a minimal model, where both Higgs and Z-mediated contributio…
How can the Standard model Higgs and also the extensions of the Higgs to Yukawa's scalars be interpreted in the spin-charge-family theory and to what predictions about the Higgs does this theory lead?
What is the W b anti-b, Z b anti-b or t anti-t b anti-b irreducible background to the light Higgs boson searches at LHC?
LHC的W b anti-b、Z b anti-b和t anti-t b anti-b产生分别是标准模型（SM）和最小超对称标准模型（MSSM）光希格斯玻色子玻色子在伴随的WH、ZH和t anti-t H产生之后的H -> b anti-b衰变中可能的可观测性的不可约背景。我们提出了一个比较的背景估计，获得（a）完整的大规模矩阵元素在AcerMC蒙特卡罗发生器和（b）PYTHIA实施的包容性W，Z，和t反t生产，其次是部分子淋浴机制。这两种方法都导致了最终感兴趣状态的产生，但在所使用的近似值上有所不同。我们集中在这些方法的比较，在LHC的光希格斯玻色子搜索的背景。
As one of the key properties of the Higgs boson, the Higgs total width is sensitive to global profile of the Higgs boson couplings, and thus new physics would modify the Higgs width. We investigate the total width in various new physics models, including various scalar extension, composite Higgs models, and fraternal twin Higgs model. Typically the Higgs width is smaller than the standard model value due to mixture with other scalar if the Higgs is elementary, or curved Higgs field space for the composite Higgs. On the other hand, except the possible invisible decay mode, the enhanced Yukawa c…
Searches for Dark Matter suggest that it couples to ordinary matter only very weakly and possibly only through the Higgs or other scalar bosons. On the other hand, neutrinos might not couple to the Higgs boson directly, but only through a loop of Dark Matter particles, which would naturally explain the small neutrino masses. We demonstrate that current experimental constraints on such a ``scotogenic'' scenario allow to make the linear dependence of the lightest neutrino mass on the dark sector-Higgs coupling explicit, so that a measurement by the KATRIN experiment would directly determine its …
We propose UV complete (Partially) Composite Higgs models with compositeness scale up to the Planck scale assisted by a novel mechanism. This mechanism is based on softly breaking a global $ \mathbb{Z}_2 $ symmetry by technically natural small vacuum misalignment, dynamically triggering the electroweak symmetry breaking and Standard Model fermion mass generation. This mechanism can be present in various models based on vacuum misalignment. For concreteness, we demonstrate it in a minimal partially composite two-Higgs scheme, where the Higgs is a mixture of a composite and an elementary state, …
