Connecting String Theory to Particle Physics

将弦理论与粒子物理学联系起来

• 批准号: 0653587
• 负责人: Brent Nelson
• 金额: $ 8.99万
• 依托单位: Northeastern University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-11-15 至 2010-10-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0653587&HistoricalAwards=false
• 关键词: Connecting; String; Theory; Particle; Physics

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.

这项提案中详细描述的研究试图在弦理论的最新进展和即将到来的欧洲核子研究中心LHC实验数据之间建立一座桥梁。由于超对称性通常是超弦低能极限的一个特性，这个提议主要涉及粒子物理学的超对称模型。为了真正与可观测世界建立联系，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，粒子内容和超势耦合;（2）它必须允许产生现实现象学的模量稳定和超对称破缺;（3）它必须能够解释在LHC和其他即将到来的实验中发现的任何新物理信号。本提案旨在应对这些挑战中的每一项。第一套项目中详细的建议关注的问题有关的几何性质的紧致化所产生的低能量理论。使用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。特别地，将确定最小超对称标准模型（MSSM）的真空流形。此外，现象学上有趣的变体将被研究，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相关性。这种思考超对称理论的新方法，最终应该会导致自上而下构建现实弦模型的数学进步。在第二套项目的完整有效的拉格朗日规范带电物质将开发的M-理论紧化流形上的G2 holonomy。这些理论还没有被详细研究，尽管它们已知会产生N = 1超对称、非阿贝尔规范理论和手征费米子的低能极限。最后一组项目将调查从LHC获得的信号中提取新物理学的基础拉格朗日的挑战。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观测量的相关影响，以及许多弦理论结构所建议的新SU（3）带电奇异夸克的研究。这项工作对更广泛社区的影响是多方面的。LHC物理学方面的工作非常适合本科生参与LHC奥林匹克系列数据挑战。这些分析的修改后的基于网络的版本将被开发作为这个建议的辅助，让高中年龄的学生体验到信号提取和发现在模拟的“LHC”的兴奋。此外，PI将参加波士顿地区的TheoryNet计划。