Origin of mass scales and hierarchies

随着大型强子对撞机运行的迫近，正在认真考虑的新物理模型的数量从未如此之多。需要新的物理学来完成我们对四种自然力中的两种统一的描述，这是几十年前的电弱相互作用标准模型所描述的。这种描述中固有的对称性破缺需要出现新的质量尺度，但对于这种质量尺度的起源还没有得到证实的理解。能量比电弱尺度低三个数量级的是QCD的质量尺度，它描述了自然界的第三种基本力。QCD的性质提供了一个例子，说明质量尺度如何在强相互作用规范理论中具有动力学起源。令人惊讶的是，大多数关于电弱质量尺度起源的建议与QCD的例子有很大的不同。流行的建议包括一些尚未在自然界中出现的概念（基本标量场、超伴子、额外维度、弦理论等）。我的研究追求更保守的方法，更符合QCD提供的线索。我将继续详细阐述这对大型强子对撞机物理学可能意味着的信号，我将继续研究剩余的质量和味道问题的相关含义。一种有趣的可能性是，强尺度相互作用也存在于引力之下，引力是自然界的第四种力。这是通过“诱导引力”现象实现的，它需要更好地理解无质量量子cd等理论中的真空能。有助于这种理解的是最近的实验、晶格研究和其他低能量QCD的非微扰方法的结果。

As the operation of the LHC looms near, the number of new physics models being seriously considered has never been greater. New physics is needed to complete our picture of the unification of the two of the four forces of nature as described by the decades old standard model of electroweak interactions. The symmetry breaking inherent in this description requires the appearance of a new mass scale, but there has been no confirmed understanding of the origin of this mass scale. At about three orders of magnitude lower in energy than the electroweak scale is the mass scale of QCD, describing a third fundamental force of nature. With QCD nature provides an example of how a mass scale can have a dynamical origin in a strongly interacting gauge theory. Surpisingly, most proposals for the origin of the electroweak mass scale differ significantly from the QCD example. The popular proposals involve concepts that have not yet been seen in nature (elementary scalar fields, superpartners, extra dimensions, string theories, etc.). My research pursues a more conservative approach, more in line with clues provided by QCD. I will continue to elaborate on the signals that this may imply for LHC physics and I will continue to study the related implications for the remaining questions of mass and flavor. An intriguing possibility is the idea that strong gauge interactions also underly gravitation, the fourth force of nature. This is through the phenomenon of "induced gravity", and it requires a better understanding of vacuum energy in theories like massless QCD. Contributing to this understanding are recent results from experiment, lattice studies, and other nonperturbative approaches to low energy QCD.