Global QCD Analysis and Electroweak Symmetry Breaking in High Energy Collider Phenomenology

高能对撞机现象学中的全局 QCD 分析和电弱对称破缺

• 批准号: 0855561
• 负责人: Chien-Peng Yuan
• 金额: $ 135万
• 依托单位: Michigan State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2015-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0855561&HistoricalAwards=false
• 关键词: Global; QCD; Analysis; Electroweak; Symmetry

Current understanding of high energy physics is embodied in the Standard Model (SM). According to that theory, protons and neutrons, along with all other strongly interacting particles, are composed of even more fundamental particles called partons (quarks and gluons). Interactions between the partons are described by the theory of Quantum Chromodynamics (QCD). The proposed research involves continued refinement in understanding the interplay between QCD theory and experiment, which is necessary to deepen the understanding of QCD and to determine the probability distributions of the partons in the proton by global analysis. The resulting CTEQ Parton Distributions are essential to the interpretation of experiments at the world's leading high energy collider facilities: Fermilab (Batavia, IL), DESY (Hamburg, Germany), RHIC (Brookhaven, NY), and CERN (Geneva, Switzerland). The Electroweak sector of the SM is extremely successful in explaining and predicting experimental data spanning a range in energy from the atomic scale to the Z boson mass.However, one major aspect of the model remains to be elucidated: the mechanism of Electroweak Symmetry Breaking (EWSB), which generates masses for the W and Z bosons while leaving electromagnetic gauge symmetry intact. In the SM, EWSB is economically implemented through a single scalar particle called the Higgs boson. However, the SM cannot explain observations such as the hierarchical pattern of fermion masses, or the existence of dark matter; so it is widely believed that new measurements at very high energies, or very high precision, will soon turn up deviations from the SM that will point to new physics.A second part of the project represents continuation of research to probe the EWSB mechanism in high energy collisions. Special consideration is given to measuring the couplings of the top quark to W and Z gauge bosons and to (elementary or composite) Higgs boson(s); and to searching for the Higgs boson and determining its properties. These are prime objectives of experiments at the Fermilab Tevatron collider and the CERN Large Hadron Collider (LHC).The broader impacts of this project are as follows: The achievement of the project will contribute to understanding of the fundamental interactions in Nature. The project trains graduate students and postdoctoral fellows in theoretical high energy physics at MSU and at the CTEQ summer schools. It also provides opportunities for undergraduate students to participate in research through the REU program, and for high school teachers and middle school students to experience forefront research through Summer programs sponsored by MSU and the State of Michigan.

当前对高能量物理学的理解体现在标准模型（SM）中。根据该理论，质子和中子以及所有其他强烈相互作用的颗粒都由更基本的颗粒组成，称为partons（夸克和胶子）。参与量之间的相互作用是通过量子染色体动力学理论（QCD）描述的。拟议的研究涉及在理解QCD理论与实验之间的相互作用方面的持续完善，这对于加深对QCD的理解并确定partons通过全球分析在质子中的概率分布是必不可少的。由此产生的CTEQ PARTON分布对于在世界领先的高能撞机设施中解释实验至关重要：Fermilab（伊利诺伊州巴达维亚），Desy（德国汉堡），Rhic（Brookhaven，NY）和CERN（瑞士日内瓦）。 SM的电动部门在解释和预测实验数据范围从原子量量表到Z boson Mass的能量范围非常成功。在SM中，EWSB通过称为Higgs玻色子的单个标量粒子在经济上实现。但是，SM无法解释观察结果，例如费米昂质量的层次结构模式或暗物质的存在。因此，人们普遍认为，以很高的能量或很高的精度，很快就会出现与SM的偏差，这将指向新的物理。给出了特殊考虑，以测量顶部夸克与W和Z仪表的耦合以及（基础或复合）higgs玻色子的耦合；并搜索希格斯玻色子并确定其性质。这些是Fermilab Tevatron对撞机和CERN大型强子对撞机（LHC）的实验的主要目标。该项目的更广泛影响如下：该项目的实现将有助于理解自然界的基本相互作用。该项目在MSU和CTEQ暑期学校训练研究生和博士后研究员。它还为本科生提供了通过REU计划参加研究的机会，以及高中教师和中学生通过MSU和密歇根州赞助的夏季计划来体验前列研究的机会。