Phenomenology from Lattice QCD and collider physics

晶格 QCD 和对撞机物理的现象学

• 批准号: ST/L000466/1
• 负责人: Christine Davies
• 金额: $ 60.7万
• 依托单位: University of Glasgow
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2014
• 资助国家: 英国
• 起止时间: 2014 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FL000466%2F1
• 关键词: Phenomenology; Lattice; QCD; collider; physics

The Glasgow theory group has a strong reputation in studies of the subatomic world, and pushing forward our understanding of how it works. This is aimed at uncovering the fundamental constituents of matter and the nature of the interactions that operate between them. There are two approaches to this, and we will use both of them. One is to perform very accurate calculations within the theoretical framework of the Standard Model that we believe correctly describes the particles that we have seen so far and the strong, weak and electromagnetic forces of Nature. Discrepancies between these accurate calculations and what is seen in experiments will then point the way to a deeper theory that describes fundamental particle physics more completely. The second method is concerned with what we might see in LHC results, now appearing, if one or other of the suggested deeper theories is correct. We must make sure that we optimise the analysis of these experiments to learn as much as possible. Accurate calculations in the Standard Model have foundered in the past on the difficult problem of how to handle the strong force. This force is important inside particles that make up the atomic nucleus, the proton and neutron and a host of similar particles called hadrons produced in high energy collisions. The constituents of these particles are quarks, and they are trapped inside hadrons by the behaviour of the strong force. This 'confinement' of quarks makes calculations of the effect of the strong force on the physics of hadrons very challenging. It can be tackled, however, using the numerical techniques of lattice QCD. This method has been tested thoroughly by the Glasgow group in precision calculations of hadron masses and their comparison to experiment, and its current acceptance as a precision tool is based in no small part on their work. Glasgow continues to lead progress and here we propose further, harder calculations that will predict more details of how hadrons decay from one type to another via the weak force. The comparison of accurate results with experiment allows us to constrain the parameters of the weak force that allow for violations of symmetry between matter and antimatter. We plan to push down errors for these calculations and that will allow us to test the Standard Model very stringently. The Glasgow team will also investigate theories that go beyond the Standard Model and test them with LHC data. The recent discovery of the Higgs boson is the last piece of the Standard Model and is a triumph for both theoretical and experimental particle physics. However, we must ensure that the particle discovered is indeed the Higgs boson of the Standard Model, so we must undertake a comprehensive programme to measure its properties. New physics may show up by subtly modifying these properties and we will devise ways of looking for these effects. The LHC will also produce large numbers of top quarks for the first time, and since the top quark is the heaviest particle in the Standard Model, one expects its properties also to be affected by new physics. So, as for the Higgs boson, we will also investigate top quark properties using a general model independent framework. We will then examine specific new physics models, such as theories of Grand Unification, which unify the three forces together as one single force. We will determine how these exciting and fundamental theories affect the particle properties described above and thereby confront them with LHC observations. Experimental studies on the Higgs boson and top quarks are being led by the Glasgow ATLAS group and we will coordinate with them to uncover the fundamental truths of the universe. The next few years will be a very exciting time for theoretical particle physics and Glasgow aims to be at the forefront of this work.

格拉斯哥理论小组在亚原子世界的研究方面享有很高的声誉，并推动了我们对其运作方式的理解。这是为了揭示物质的基本成分和它们之间相互作用的本质。有两种方法，我们将使用这两种方法。一个是在标准模型的理论框架内进行非常精确的计算，我们相信标准模型正确地描述了我们迄今为止所看到的粒子以及自然界的强、弱和电磁力。这些精确的计算结果与实验结果之间的差异将为更全面地描述基本粒子物理学的更深层次的理论指明道路。第二种方法关注的是，如果提出的更深层次理论中的一个或另一个是正确的，我们可能会在LHC的结果中看到什么。我们必须确保我们优化这些实验的分析，以尽可能多地学习。在过去，标准模型中的精确计算在如何处理强作用力的难题上失败了。这种力在组成原子核、质子和中子的粒子以及在高能碰撞中产生的大量被称为强子的类似粒子中很重要。这些粒子的成分是夸克，它们被强力的作用困在强子里。夸克的这种“约束”使得强子物理中强作用力的计算非常具有挑战性。然而，这个问题可以用点阵QCD的数值技术来解决。这种方法已经被格拉斯哥小组在强子质量的精确计算和与实验的比较中进行了彻底的测试，目前它作为一种精密工具被接受，在很大程度上是基于他们的工作。格拉斯哥继续引领进展，在这里我们提出进一步，更困难的计算，将预测更多的细节强子如何通过弱力从一种类型衰变到另一种类型。精确结果与实验结果的比较使我们能够约束弱力的参数，这些参数允许物质和反物质之间的对称性被破坏。我们计划降低这些计算的误差，这将使我们能够非常严格地测试标准模型。格拉斯哥研究小组还将研究超越标准模型的理论，并用大型强子对撞机的数据对它们进行检验。最近发现的希格斯玻色子是标准模型的最后一块，是理论和实验粒子物理学的一次胜利。然而，我们必须确保发现的粒子确实是标准模型中的希格斯玻色子，因此我们必须开展一个全面的计划来测量它的性质。通过微妙地改变这些特性，可能会出现新的物理现象，我们将设计出寻找这些效应的方法。大型强子对撞机还将首次产生大量顶夸克，由于顶夸克是标准模型中最重的粒子，人们预计它的性质也会受到新物理学的影响。因此，对于希格斯玻色子，我们也将使用一般模型独立框架来研究顶夸克的性质。然后，我们将研究具体的新物理模型，如大统一理论，它将三种力统一为一种力。我们将确定这些激动人心的基本理论是如何影响上述粒子特性的，从而用大型强子对撞机的观测结果来对抗它们。希格斯玻色子和顶夸克的实验研究由格拉斯哥ATLAS小组领导，我们将与他们合作，揭开宇宙的基本真相。未来几年将是理论粒子物理学非常激动人心的时刻，格拉斯哥的目标是走在这项工作的前沿。

项目成果

The Kerr-Schild double copy in curved spacetime

• DOI: 10.1007/jhep12(2017)004
• 发表时间: 2017-10
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: N. Bahjat-Abbas;A. Luna;C. White

Next-to-leading power threshold logarithms: a status report

次领先的功率阈值对数：状态报告

• DOI: 10.48550/arxiv.1602.01988
• 发表时间: 2016
• 期刊: arXiv e-prints
• 作者: Bonocore Domenico

A factorization approach to next-to-leading-power threshold logarithms

• DOI: 10.1007/jhep06(2015)008
• 发表时间: 2015-03
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: Domenico Bonocore;E. Laenen;E. Laenen;L. Magnea;S. Melville;L. Vernazza;Chris D. White

Higgs self-coupling measurements at a 100 TeV hadron collider

• DOI: 10.1007/jhep02(2015)016
• 发表时间: 2014-12
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: A. Barr;M. Dolan;C. Englert;D. D. Lima-D.;M. Spannowsky

A to Z of the muon anomalous magnetic moment in the MSSM with Pati-Salam at the GUT scale

• DOI: 10.1007/jhep06(2016)142
• 发表时间: 2016-05
• 期刊: Journal of High Energy Physics
• 影响因子: 5.4
• 作者: A. Belyaev;J. E. Camargo-Molina;S. King;David J. Miller;A. Morais;P. B. Schaefers