Phenomenology from Lattice QCD and collider physics

格拉斯哥理论小组在亚原子世界的研究方面享有盛誉，并推动了我们对它如何工作的理解。这是为了揭示物质的基本组成和它们之间相互作用的性质。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。这些精确的计算和实验中看到的结果之间的差异将为更完整地描述基本粒子物理学的更深入的理论指明道路。第二种方法关注的是，如果所提出的一个或另一个更深层次的理论是正确的，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。过去，标准模型的精确计算在如何处理强作用力的难题上失败了。这种力在构成原子核、质子和中子的粒子内部很重要，在高能碰撞中产生了大量类似的粒子，称为强子。这些粒子的成分是夸克，它们被强作用力的行为困在强子内部。夸克的这种“禁闭”使得计算强作用力对强子物理学的影响非常具有挑战性。然而，它可以用格点QCD的数值技术来解决。格拉斯哥小组在强子质量的精确计算及其与实验的比较中彻底地检验了这种方法，它目前作为一种精确工具的接受程度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，我们提出了进一步的，更困难的计算，将预测强子如何通过弱力从一种类型衰变到另一种类型的更多细节。精确的结果与实验的比较使我们能够限制弱力的参数，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。格拉斯哥团队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进行测试。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胜利。然而，我们必须确保所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项全面的计划来测量其属性。新的物理学可能会通过巧妙地修改这些性质而出现，我们将设计出寻找这些效应的方法。LHC也将首次产生大量的顶夸克，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，我们也将使用一般的模型独立框架来研究顶夸克的性质。然后，我们将研究特定的新物理模型，如大统一理论，它将三种力统一为一种力。我们将确定这些令人兴奋的基本理论如何影响上述粒子性质，从而用LHC观测来对抗它们。对希格斯玻色子和顶夸克的实验研究正在由格拉斯哥ATLAS小组领导，我们将与他们协调，以揭示宇宙的基本真理。未来几年将是一个非常令人兴奋的时间理论粒子物理和格拉斯哥的目标是在这项工作的最前沿。

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.