Particles, Fields and Extended Objects

粒子、场和扩展对象

基本信息

批准号：
ST/T000694/1
负责人：
Benjamin Allanach
金额：
$ 233.63万
依托单位：
University of Cambridge
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2020
资助国家：
英国
起止时间：
2020 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=ST%2FT000694%2F1
关键词：
Particles Fields Extended Objects

项目摘要

The STFC research programme of the Theoretical High Energy Physics Group atCambridge University is focused on the fundamental problems of colliderphenomenology, quantum field theory, string theory and gravity, and analysing aclass of strongly interacting particles called hadrons.In this research, weshall perform calculations to understand the fundamentals underlyingreality and our understanding of the universe and matter within it. Much of this effort supports particle physics experiments at CERN andelsewhere, as well as astrophysical and cosmological observations of theuniverse.Technical, difficult and detailed calculations deep in the quantum theory arerequired in order to interpret some of the experimental data and to learneverything we can from them. The structure of the proton (the particlescollided at the Large Hadron Collider) will be understood better in order to getrobust and reliable predictions on the collisions. We are analysingand interpreting Large Hadron Collider data from CERN to do various things: looking for signs of new particles or forces, developingsearch and measurement strategies for them, or making high precisionpredictions of various theories. The Standard Model is the current model ofparticle physics that is well accepted, verified and measured. Most of itspredictions agree well with collider data. However, it leaves many questionsunanswered: why do the fundamental particles have the particular pattern theydo in their masses? We shall be developing mathematical models, based oncurrent data, to try to explain some such features, and provide experimentaltests at the same time. We are also busy supporting the science case for futurecolliders, investigating which questions they could answer well.How gravity behaves at small distance scales is badly understoodtheoretically, although string theory may be an interesting framework forunderstanding it.We will be developing and investigating theories of quantumgravity mathematically in order to push the understanding forward.Blackholes provide a particular focus for the calculations: these are objectsaround which gravity is very strong, and we will learn much from theirtheoretical study. Variouscalculations in new developments of string theory are important for this, andfor the development of how to calculate particle scattering in general. String theories will be constructed to see how close they come to the universewe see. Also, models of inflation (a time in the early universe when theuniverse underwent extremely rapid expansion) will be investigated, developedand compared with observations.Some particles, such as hadrons, are strongly bound states of smaller ones. For these, sophisticated computer programs are built which break space and time up into a grid of points, and the quantumfluctuations of the sub-nuclear interactions are simulated using randomnumbers on this lattice. Analytic calculations must be done to match thenumbers obtained on the computer to experimental data. We shall develop these calculations, and perform new ones so that data can be used to extract the level to which various quarks (for example, the up quark and the b-quark) mix. This helps provide an accurate description of an unexplained phenomenon: how the funny pattern of quark mixing comes about. These calculations also help the extraction of the difference between matter and anti-matter from experimental data. We can predict much about which strongly bound states may exist and their properties, and studies of the more exotic and puzzling varieties seen in experiment will be an important avenue of work.

剑桥大学理论高能物理组的 STFC 研究项目专注于对撞现象学、量子场论、弦理论和引力的基本问题，并分析一类称为强子的强相互作用粒子。在这项研究中，我们将通过计算来理解现实的基本原理以及我们对宇宙和其中物质的理解。这项工作的大部分支持欧洲核子研究中心和其他地方的粒子物理实验，以及对宇宙的天体物理学和宇宙学观测。为了解释一些实验数据并从中了解我们可以学到的一切，需要量子理论深处的技术性、困难性和详细的计算。质子（在大型强子对撞机中碰撞的粒子）的结构将得到更好的理解，以便对碰撞进行稳健且可靠的预测。我们正在分析和解释来自欧洲核子研究中心的大型强子对撞机数据，以完成各种任务：寻找新粒子或力的迹象，为其制定搜索和测量策略，或者对各种理论进行高精度预测。标准模型是当前被广泛接受、验证和测量的粒子物理模型。它的大部分预测与对撞机数据非常吻合。然而，它留下了许多悬而未决的问题：为什么基本粒子的质量具有特定的模式？我们将根据当前数据开发数学模型，尝试解释一些此类特征，同时提供实验测试。我们还忙于支持未来对撞机的科学案例，研究它们可以很好地回答哪些问题。虽然弦理论可能是理解它的一个有趣的框架，但理论上对引力在小距离尺度上的表现知之甚少。我们将开发和研究量子引力理论黑洞为计算提供了一个特别的焦点：这些物体周围的引力非常强，我们将从它们的理论研究中学到很多东西。弦理论新发展中的各种计算对此非常重要，对于一般计算粒子散射的方法的发展也很重要。我们将构建弦理论来看看它们与我们所看到的宇宙有多接近。此外，还将研究、开发膨胀模型（宇宙早期宇宙经历极其快速膨胀的时期），并与观测结果进行比较。一些粒子，例如强子，是较小粒子的强束缚态。为此，构建了复杂的计算机程序，将空间和时间分解为点网格，并使用该网格上的随机数模拟亚核相互作用的量子涨落。必须进行分析计算以使计算机上获得的数字与实验数据相匹配。我们将开发这些计算，并执行新的计算，以便可以使用数据来提取各种夸克（例如，上夸克和b夸克）混合的水平。这有助于准确描述无法解释的现象：夸克混合的有趣模式是如何产生的。这些计算还有助于从实验数据中提取物质和反物质之间的差异。我们可以预测可能存在哪些强束缚态及其性质，并且对实验中看到的更奇特和令人费解的品种的研究将是一个重要的工作途径。