Connecting String Theory to Particle Physics

这项提案中详细介绍的研究旨在在弦理论的最新进展和欧洲核子研究中心（CERN）即将进行的大型强子对撞机实验数据之间建立一座桥梁。由于超对称经常作为超弦低能极限的一个特性出现，这个提议很大程度上涉及粒子物理的超对称模型。为了真正与可观测世界接触，候选弦模型必须在三个方面取得成功：(1)它必须产生标准模型的量规群、粒子含量和超势耦合；(2)它必须允许模稳定和产生现实现象学的超对称破缺；(3)它必须能够解释在大型强子对撞机和其他即将进行的实验中发现的任何新的物理信号。本提案旨在应对这些挑战。提案中详细介绍的第一组项目涉及将紧化的几何性质与由此产生的低能理论联系起来的问题。利用PI及其合作者开发的新技术，将确定并编目由N = 1超对称规范理论的模空间描述的真空流形。特别地，将确定最小超对称标准模型（MSSM）的真空流形。此外，将研究现象学上有趣的变体，以努力找到这些理论的物理学与其模空间的几何之间的相关性。这种思考超对称理论的新方法最终将导致现实弦模型的自顶向下构造的数学进步。在第二组项目中，将针对G2完整流形上的m -理论紧化发展规范带电物质的完全有效拉格朗日量。这些理论尚未被详细研究，尽管已知它们会产生N = 1超对称、非阿贝尔规范理论和手性费米子的低能极限。最后一组项目将研究从大型强子对撞机获得的信号中提取新物理学的潜在拉格朗日量的挑战。这个问题将从其中的许多角度进行研究，研究新物理模型对顶夸克观测值的相关影响，以及许多弦理论构造所建议的新的带S(3)电荷的奇异夸克的研究。这项工作对更广泛的社区的影响是多方面的。大型强子对撞机物理方面的工作非常适合本科生参与大型强子对撞机奥林匹克系列数据挑战。这些分析的一个修改后的网络版本将作为该提案的补充，让高中生在模拟的“大型强子对撞机”中体验信号提取和发现的兴奋。此外，PI将参与波士顿地区的理论网络计划。

The research detailed in this proposal seeks to build a bridge between recent advances in string theory and the forthcoming data from the LHC experiment at CERN. As supersymmetry often emerges as a property of the low-energy limit of superstrings, the proposal largely involves supersymmetric models of particles physics. To truly make contact with the observable world a candidate string model must succeed on three fronts: (1) it must produce the Standard Model gauge group, particle content and superpotential couplings; (2) it must allow for moduli stabilization and supersymmetry breaking that produces a realistic phenomenology; and (3) it must be capable of explaining any new physics signals found at the LHC and other upcoming experiments. This proposal seeks to attack each of these challenges. The first set of projects detailed in the proposal concern the issue of relating geometrical properties of compactifications to the resulting low energy theory. Using new techniques developed by the PI and collaborators, the vacuum manifold described by the moduli space of N = 1 supersymmetric gauge theories will be determined and catalogued. In particular, the vacuum manifold for the minimal supersymmetric standard model (MSSM) will be determined. In addition, phenomenologically interesting variants will be studied in an effort to find correlations between the physics of these theories and the geometry of their moduli spaces. This new way of thinking about supersymmetric theories should eventually lead to progress in the mathematics of top-down constructions of realistic string models. In the second set of projects the complete effective Lagrangian for gauge-charged matter will be developed for M-theory compactifications on manifolds of G2 holonomy. Such theories have yet to be studied in detail, though they are known to give rise to low-energy limits with N = 1 supersymmetry, non-Abelian gauge theories and chiral fermions. The final set of projects will investigate the challenges for extracting the underlying Lagrangian for new physics from the signals to be obtained at the LHC. The problem will be investigated from a number of angles among them, looking at correlated effects of new physics models on top quark observables and the study of new S U (3)-charged exotic quarks as suggested by many string-theory constructions. The impacts of this work on the broader community are many. Work on LHC physics lends itself very well to the participation of undergraduates in the LHC Olympics series of data challenges. A modified web-based version of these analyses will be developed as an adjunct to this proposal to let high-school age students experience the excitement of signal extraction and discovery at a simulated 'LHC'. In addition the PI will be participating in the Boston-area TheoryNet program.