Standard Model Phenomenolgy.

基思汉密尔顿的研究涉及到高精度蒙特卡罗模拟对撞机物理过程的发展。这些都有助于在大型强子对撞机（LHC）上发现和解释新物理。虽然可能不需要精确的模拟来宣布一项发现，例如，如果新的物理学在光滑分布中出现明显的"凸起"（如希格斯玻色子），在许多情况下，如超对称性，信号预计将表现为分布形状的微妙扭曲。准确理解标准模型的背景，服从于所有的实验切割，然后是不可避免的声称一个发现，或设置排除限制。精确的模拟对于确定所发现的是什么也是必不可少的，最近发现的125 GeV质量的希格斯玻色子就是最好的例子。在2012 - 2013年，汉密尔顿与米兰和牛津的合作者开发了世界上最精确的希格斯玻色子生产模拟。这种模拟现在被ATLAS和CMS合作默认使用，出现在他们的出版物中，面对探测希格斯玻色子性质的测量。近年来，汉密尔顿的工作已经展示了如何将尖端模拟背后的方法扩展到更广泛的大型强子对撞机反应。在未来的几年里，汉密尔顿将作为一个新团队的一部分工作，该团队由另外三名世界级的研究人员组成，以扩展最核心的部分子簇射，通用蒙特卡罗事件发生器的组成部分-粒子物理学中最广泛使用的理论工具。通用事件发生器是对撞机物理学的核心，影响着整个社区。索恩的工作是对汉密尔顿的补充。它涉及强子粒子碰撞中出现的初始状态的精确细节。在强子对撞机中，例如大型强子对撞机（LHC），粒子束有效地由质子内部的基本粒子组成-夸克和胶子，一般称为部分子。对标准模型过程的预测，以及潜在的新物理学的预测，需要强子在散射过程的能量标度（例如，产生的粒子的质量）和由部分子携带的入射质子的动量分数。索恩是一个已建立的PDF组的领导成员，该组提供了一组部分子分布函数（PDF），用于LHC和其他高能粒子物理实验的实验和理论分析。该方法不断完善，无论是在理论上的复杂性，并通过纳入数据变得可用，并由于提高精度或不同的敏感性PDF，导致进一步的PDF约束。Thorne的工作将改进PDF的确定，提供更新的PDF供普遍使用，他还将调查任何变化的后果。这将有助于更好地了解当前和即将到来的测量，也将影响未来高能粒子物理实验的规划。此外，索恩是PDF4LHC工作组的核心成员（自成立以来一直是指导委员会的成员，也是主要的推动者和组织者之一），为LHC使用PDF集提供建议，并作为LHC实验社区的直接联络人。汉密尔顿和索恩都参与了LHC不断提高的计算精度，这对于最大限度地发挥大型强子对撞机的潜力尤其重要，特别是考虑到目前没有新物理学的明确信号，但标准模型测试的前所未有的多样性和精度不断出现。两者都将提供解释任何偏差的专业知识，这些偏差可能是超越标准模型（BSM）物理学的第一个迹象。

Keith Hamilton's research concerns the development of high precision Monte Carlo simulations of collider Physics processes. These facilitate discovery and interpretation of new physics at the Large Hadron Collider (LHC). While precision simulations may not be needed to claim a discovery, e.g. if new physics appears as a clear `bump' in a smooth distribution, (as did the Higgs boson), in many scenarios, such as supersymmetry, signals are expected to manifest as subtle distortions in the shapes of distributions. An accurate understanding of the Standard Model background, subject to all experimental cuts, is then unavoidable for claiming a discovery, or setting exclusion limits. Precision simulations are also essential to determine what it is that has been found. The recently discovered 125 GeV mass Higgs boson is the prime example of this. In 2012-2013 Hamilton and collaborators in Milan and Oxford developed the world's most accurate simulation of Higgs boson production. This simulation is now used by default by the ATLAS and CMS collaborations, appearing in their publications confronted with measurements to probe Higgs boson properties. In recent years Hamilton's work has shown how to extend the methodology behind that cutting-edge simulation to an important wider range of LHC reactions. In the coming years Hamilton will work as part of a new team, comprising three other world-class researchers, to extend the most central, parton shower, component of general purpose Monte Carlo event generators -- the most widely used theoretical tools in particle physics. General purpose event generators are at the heart of the way in which collider physics is carried out, impacting on the whole community. Thorne's work is complementary to that of Hamilton. It involves the precise details of the initial state appearing in hadronic particle collisions. At hadron colliders, e.g. the Large Hadron Collider (LHC), the particle beam is effectively made up of the fundamental particles inside the proton - quarks and gluons, generically known as partons. Predictions for Standard Model processes, and potentially those of new physics, require the precise partonic composition of the hadrons in terms of both the energy scale of the scattering process (e.g., the mass of a particle produced) and the momentum fraction of the incoming proton carried by the parton. Thorne is the lead member of an established PDF group that provides one of sets of parton distribution functions (PDFs) used as standard by both the experimental and theoretical analyses at the LHC and other high energy particle physics experiments. The approach is continually refined, both in terms of theoretical sophistication, and by inclusion of data which become available and due to increased precision or different sensitivity to PDFs, lead to further PDF constraints. Thorne's work will lead to improved PDF determination, providing updated PDFs for universal use, and he will also investigate the consequences of any changes. This will lead to a better understanding of current and upcoming measurements, and will also influence planning for future high energy particle physics experiments. Additionally, Thorne is a core member of the PDF4LHC working group (a member of the steering committee since the inception, and one of the main drivers and organisers) which provides recommendations for use of PDF sets at the LHC and acts as a direct liason to the LHC experimental community.Both Hamilton and Thorne are involved in ever increasing precision for calculations at the LHC, which is particularly essential in order maximise the potential of the LHC, particularly given the current situation of no clear signals of new physics, but continual appearance of unprecedented variety and precision of Standard Model tests. Both will provide expertise in interpretingany deviations which could be the first sign of Beyond the Standard Model (BSM) Physics.