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.

该提案中详细介绍的研究旨在在弦理论的最新进展与欧洲核子研究中心大型强子对撞机实验即将发布的数据之间架起一座桥梁。由于超对称性经常作为超弦低能极限的属性出现，因此该提议主要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组、粒子含量和超电势耦合； （2）它必须允许模量稳定和超对称破缺，从而产生现实的现象学； (3)它必须能够解释大型强子对撞机和其他即将进行的实验中发现的任何新物理信号。该提案旨在应对这些挑战。该提案中详细介绍的第一组项目涉及将致密化的几何性质与由此产生的低能理论联系起来的问题。使用 PI 和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。特别是，将确定最小超对称标准模型（MSSM）的真空歧管。此外，还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形状之间的相关性。这种关于超对称理论的新思维方式最终应该会导致现实弦模型自上而下构造的数学进步。在第二组项目中，将开发用于规范带电物质的完整有效拉格朗日，用于 G2 完整流形上的 M 理论紧致化。这些理论尚未得到详细研究，但已知它们会产生 N = 1 超对称、非阿贝尔规范理论和手性费米子的低能量极限。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的基础拉格朗日量的挑战。该问题将从多个角度进行研究，研究新物理模型对顶夸克可观测量的相关影响，以及许多弦理论结构所建议的新 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很多影响。大型强子对撞机物理研究非常适合本科生参与大型强子对撞机奥运会系列数据挑战。这些分析的修改版基于网络的版本将作为该提案的附件而开发，让高中生体验在模拟“大型强子对撞机”中提取和发现信号的兴奋感。此外，PI 将参与波士顿地区的 TheoryNet 计划。