Connecting String Theory to Particle Physics

这项建议中详述的研究试图在弦理论的最新进展和欧洲核子研究中心大型强子对撞机实验即将公布的数据之间架起一座桥梁。由于超对称性经常作为超弦的低能极限的一种属性出现，该提议在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规范群、粒子含量和超势耦合；(2)它必须考虑到模数稳定和超对称破缺，从而产生现实的现象学；(3)它必须能够解释在大型强子对撞机和其他即将到来的实验中发现的任何新的物理信号。这项提案试图应对这些挑战中的每一个。提案中详述的第一组项目涉及将压实的几何特性与由此产生的低能量理论联系起来的问题。利用PI和合作者开发的新技术，将确定和编目由N=1超对称规范理论的模空间描述的真空流形。特别是，将确定最小超对称标准模型(MSSM)的真空流形。此外，还将研究现象上有趣的变体，以努力找到这些理论的物理学和它们的模空间的几何之间的关联。这种关于超对称理论的新思维方式最终应该会在自上而下构建现实弦模型的数学方面取得进展。在第二组项目中，将为G2完整力学流形上的M理论紧致发展完整的规范带电物质的有效拉格朗日。这些理论尚未被详细研究，尽管它们已知会产生具有N=1超对称性的低能量极限、非阿贝尔规范理论和手征费米子。最后一组项目将调查从大型强子对撞机上获得的信号中提取新物理的潜在拉格朗日量所面临的挑战。这个问题将从多个角度进行研究，其中包括新物理模型对顶夸克可观测量的关联效应，以及许多弦理论结构所建议的对新的S U(3)带电奇异夸克的研究。这项工作对更广泛的社区产生了许多影响。大型强子对撞机物理方面的工作非常适合参加大型强子对撞机奥运会系列数据挑战的本科生。这些分析的修改后的网络版本将作为这项提议的补充，让高中生体验在模拟的大型强子对撞机上提取和发现信号的兴奋。此外，PI还将参加波士顿地区的TheoryNet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.