Global QCD Analysis and Precision Electroweak Physics in High Energy Collider Phenomenology

高能对撞机现象学中的全局 QCD 分析和精密电弱物理

• 批准号: 1417326
• 负责人: Chien-Peng Yuan
• 金额: $ 72万
• 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: 2014
• 资助国家: 美国
• 起止时间: 2014-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1417326&HistoricalAwards=false
• 关键词: Global; QCD; Analysis; Precision; Electroweak

This award funds the research activities of Professors Jon Pumplin, Daniel Stump and C.-P. Yuan at the Michigan State University (MSU).Support for this project will contribute to understanding the fundamental nature of the physical universe--the particles that comprise it and their interactions--as revealed by experiments in high energy physics. Current understanding of high energy physics is embodied in the Standard Model (SM). Protons and neutrons, and all other strongly interacting particles, are composed of fundamental particles called partons (quarks and gluons). Interactions between the partons are described by the theory of Quantum Chromodynamics (QCD). The proposed research involves the interplay between QCD theory and experimental data from many experiments, including recent experiments at the CERN Large Hadron Collider (LHC). This global analysis of data is necessary to deepen the understanding of QCD, and to determine the probability distributions of the partons in the proton. By understanding these distributions, it is possible to take interactions of protons with protons (which is what happens at the LHC) and determine the underlying quark-quark, quark-gluon and gluon-gluon interactions. This is essential for determining the underlying physics of the process, and was necessary for extracting, for example, the Higgs boson signal. These probability distributions are called "CTEQ Parton Distribution Functions", where CTEQ means "Coordinated Theoretical-Experiment Project of QCD". The project trains graduate students and postdoctoral fellows in theoretical high energy physics at MSU and at CTEQ summer schools. It also provides opportunities for undergraduate students to participate in forefront research through the REU program, and for high school teachers and middle school students to experience physics through summer programs sponsored by MSU and the State of Michigan.As noted, the resulting CTEQ Parton Distribution Functions have been essential to the interpretation of experiments at the world's leading high energy collider facilities: Fermilab (Batavia, IL), RHIC (Brookhaven, NY), DESY (Hamburg, Germany), and CERN (Geneva, Switzerland). Although the colliders at Fermilab and DESY have been turned off, data from those facilities are still important; in particular, final data from HERA run II are still to be incorporated in the present analysis when they become available. The proposed research will continue the PIs' world-leading contributions to lepton-hadron and hadron-hadron collider phenomenology. Complementary to the research on QCD, the group will also study the Electroweak (EW) sector of the SM, which is extremely successful in explaining and predicting experimental data spanning a range in energy from the atomic scale to the Z boson and top quark masses. Measurements of W, Z, top quark pair, single top quark and Higgs boson productions at the LHC, including both inclusive rates and relevant kinematical distributions, will provide major new input to the understanding of parton distributions during the next few years. At the same time, refinements of the parton distributions are necessary for progress in the EW sector, both for testing the SM in greater precision and for probing New Physics effects in high energy colliders.

该奖项资助了密歇根州立大学的Jon Pumplin、Daniel Stump和C.P.袁教授的研究活动。对该项目的支持将有助于理解高能物理实验揭示的物理宇宙的基本性质--组成它的粒子及其相互作用。目前对高能物理的理解体现在标准模型(SM)中。质子和中子，以及所有其他强相互作用的粒子，都是由称为部子(夸克和胶子)的基本粒子组成的。部分子间的相互作用用量子色动力学(QCD)理论来描述。这项拟议的研究涉及QCD理论和许多实验的实验数据之间的相互作用，包括最近在CERN大型强子对撞机(LHC)上的实验。这种对数据的全球分析对于加深对QCD的理解和确定质子中部子的概率分布是必要的。通过了解这些分布，有可能获得质子与质子的相互作用(这是在大型强子对撞机上发生的)，并确定潜在的夸克-夸克、夸克-胶子和胶子-胶子相互作用。这对于确定这一过程的基本物理过程至关重要，对于提取希格斯玻色子信号也是必要的。这些几率分布被称为“CTEQ部分子分布函数”，其中CTEQ的意思是“QCD理论-实验协调计划”。该项目在密歇根州立大学和CTEQ暑期学校培训理论高能物理的研究生和博士后研究员。它还为本科生提供了通过REU项目参与前沿研究的机会，并为高中教师和中学生提供了通过密歇根州立大学和密歇根州赞助的暑期项目体验物理的机会。如上所述，由此产生的CTEQ部分子分布函数对于解释世界领先的高能对撞机设施的实验至关重要，这些设施包括：费米实验室(伊利诺伊州巴达维亚)、RHIC(布鲁克海文，纽约)、DESY(德国汉堡)和CERN(瑞士日内瓦)。尽管费米实验室和DESY的对撞机已经关闭，但来自这些设施的数据仍然很重要；特别是HERA Run II的最终数据，当它们可用时，仍将纳入本分析。这项拟议的研究将继续PI对轻子-强子和强子-强子对撞机现象的世界领先贡献。作为对QCD研究的补充，该小组还将研究SM的电弱(EW)部分，该部分在解释和预测从原子尺度到Z玻色子和顶夸克质量的能量范围内的实验数据方面非常成功。在大型强子对撞机上测量W、Z、顶夸克对、单顶夸克和希格斯玻色子的产生，包括包含率和相关的运动学分布，将为理解未来几年的部分子分布提供重要的新信息。与此同时，为了更精确地测试SM和探索高能对撞机中的新物理效应，对电子战部门的进展来说，对部分子分布的改进是必要的。