Origin of mass scales and hierarchies

随着大型强子对撞机运行的临近，被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自然界四种力中的两种的统一的描述，正如几十年前的电弱相互作用标准模型所描述的那样。这种描述中固有的对称性破缺需要一个新的质量尺度的出现，但对这个质量尺度的起源还没有确定的理解。QCD的质量标度在能量上比电弱标度低大约三个数量级，描述了自然界的第三种基本力。QCD性质提供了一个例子，说明质量标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标度起源的提议与QCD的例子有很大的不同。流行的提议涉及到一些在自然界中还没有出现过的概念（基本标量场、超伙伴、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可能暗示LHC物理学的信号，我将继续研究剩余的质量和味道问题的相关含义。一个有趣的可能性是，强规范相互作用也是自然界第四种力引力的基础。这是通过“诱导引力”现象，它需要更好地理解无质量QCD等理论中的真空能量。对这种理解的贡献是最近的结果，从实验，晶格研究，和其他非微扰的方法，以低能量QCD。

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.