Electroweak and Strong Interactions at Very High Energies: Precision Tests of the Standard Model and Beyond

今天，粒子物理的标准模型(SM)为描述物质基本成分的电磁、弱和强相互作用提供了一个经过充分测试的框架。SM成功地描述了目前观察到的所有物质粒子(夸克和轻子)以及基本力的介体(光子、W玻色子和Z玻色子，以及胶子)之间的电弱和强相互作用。然而，由于SM的明显缺陷(例如，层级问题、微调、高能下缺乏规范耦合统一)，人们通常认为它仅仅是一个更基本的理论的低能极限，它具有额外的对称性，如超对称性(SUSY)，连接费米子和玻色子的额外对称性或具有额外空间维度的对称性。目前和未来对撞机实验的主要目标是进一步测试SM并探测新物理的信号，直接(通过产生非SM粒子)或间接(作为与SM粒子预测性质的微小偏差)。PIS建议调查顶夸克和希格斯玻色子相互作用中可能偏离SM的情况，并开发改进的理论计算和计算工具，这是在费米实验室Tevatron、CERN大型强子对撞机(LHC)和未来的国际e+e&amp；(ILC)线性对撞机(ILC)上执行SM和SUSY粒子精度研究所需的改进理论计算和计算工具。为了从这些实验中提取精确的物理信息，理论预测必须与实验精度相匹配或超过实验精度。鉴于预期的实验精度，目前的预测必须加以改进。这将首先涉及辐射修正的计算，然后在蒙特卡罗事件发生器中进行真实模拟。拟议活动的更广泛影响是，这项研究将有助于更好地理解基本粒子及其相互作用的性质。开发的工具将公之于众，并将帮助实验高能物理界充分开发目前和未来对撞机实验的潜力，以测试SM和搜索新物理的信号。这个项目将为本科生和研究生提供一个极好的培训基础，教给他们超出粒子物理研究范围的有价值的技能。拟议的活动将与世界各地的科学家合作进行，部分是在美国直线对撞机物理小组的背景下进行的，并将进一步推动美国和国际的联合科学努力。

Today, the Standard Model (SM) of particle physics provides a thoroughly tested framework for describing electromagnetic, weak and strong interactions of the fundamental constituents of matter. The SM successfully describes all presently observed electroweak and strong interactions of matter particles (quarks and leptons) and of the mediators of the fundamental forces (photon, W and Z bosons, and the gluon). However, due to apparent shortcomings of the SM (e.g., hierarchy problem, fine tuning, absence of gauge-coupling unification at high energies), it is commonly believed that it is merely the low-energy limit of a more fundamental theory, which has additional symmetries such as Supersymmetry (SUSY), an additional symmetry that connects fermions and bosons or which has extra spatial dimensions. The main goal of present and future collider experiments is to further test the SM and to detect signals of new physics, either directly (through the production of non-SM particles), or indirectly (as small deviations from the predicted properties of SM particles).The PIs propose to investigate possible deviations from the SM in the interactions of top quarks and Higgs bosons, and to develop improved theoretical calculations and computational tools which are needed to perform precision studies of SM and SUSY particles at the Fermilab Tevatron, the CERN Large Hadron collider (LHC), and a future International e+e− Linear Collider (ILC). In order to extract precise physics information from these experiments, theoretical predictions must match or exceed the experimental accuracy. In light of the anticipated experimental accuracy, current predictions must be improved. This will involve first the calculation of radiative corrections and then their implementation in Monte Carlo event generators for realistic simulations.The broader impact of the proposed activities is that the research will contribute to an improved understanding of the properties of elementary particles and their interactions. The tools developed will be made publicly available and will help the experimental high-energy physics community to fully exploit the potential of present and future collider experiments for testing the SM and searching for signals of new physics. This project will provide an excellent training ground for students at both the undergraduate and graduate level, teaching them skills valuable beyond the scope of particle physics research. The proposed activities will be pursued in collaboration with scientists worldwide, partly in context of the American Linear Collider Physics Group, and will further US-international joint scientific efforts.