Manchester Particle Theory Consolidated Grant 2022 : Particle Physics in Colliders and the Cosmos

粒子物理学有一个雄心勃勃的目标：在最基本的层面上理解我们的宇宙。这意味着发现所有基本粒子，这些基本粒子是物质的最终组成部分，并了解支配它们相互作用的规律。目前的理论被称为粒子物理标准模型，几十年来，它在解释所有高能粒子对撞机实验的实验数据方面取得了显著成功，包括欧洲核子研究中心目前的大型强子对撞机的数据。然而，也非常清楚的是，在标准模型之外存在着物理学，它一直在躲避我们，等待着我们的发现。例如，我们知道物质宇宙的很大一部分是由“暗物质”组成的，这是标准模型无法解释的。我们的科学家是标准模型物理以及超越标准模型的粒子物理理论以及它们在对撞机和宇宙学数据中可能的表现方面的专家。我们建议利用这种专业知识来最大限度地发现新物理的前景。发现的主要途径之一是用同样精确的理论预测来对抗准确的大型强子对撞机数据，以寻找与当前理论的偏差，这将标志着新的物理学。希格斯玻色子的发现具有里程碑意义，它涉及质量的起源，为进一步探索提供了一条令人兴奋的途径。通常被描述为标准模型拼图的最后一块，这种粒子的真正性质还没有弄清楚，任何与教科书中的希格斯玻色子的偏离都可能预示着新的物理学。我们在强相互作用理论(QCD)方面的专业知识对于大型强子对撞机的此类研究至关重要，大型强子对撞机在高能下将质子碰撞在一起，在那里强相互作用无处不在。我们专门从事从QCD派生的算法的构建，并导致可以直接与数据进行比较的大型强子对撞机的完整计算机模拟。我们提出的研究目标之一是设计新的基于QCD的算法，以各种方式改善当前的技术水平。我们也是大型强子对撞中形成的“喷流”物理学方面的专家。在我们的提案中，我们的目标是开发新的方法，使我们能够区分标准模型粒子产生的喷流和来自新粒子的喷流，从而增强LHC的发现潜力。如果在实验数据中看到与标准模型预期的偏差，我们需要能够用标准模型以外的物理理论来解释它们。我们提议的研究包括继续构建令人信服的新物理模型，并在大型强子对撞机上调查它们的签名。我们研究的另一个部分包括积极探索标准模型没有回答的一些关键问题。其中一个问题涉及我们宇宙中物质超过反物质的问题，我们建议使用最新的大型强子对撞机数据来研究直接相关的问题。另一个方向涉及在对撞机和其他地方寻找新粒子，这些粒子可能是暗物质的候选者。我们的科学家拥有暗物质理论的专业知识，他们建议研究大型强子对撞机的数据，并结合天体物理观测和专门的暗物质搜索，以发现暗物质的起源。标准模型的另一个不足之处是解释导致宇宙加速膨胀的“暗能量”，这方面有压倒性的证据。我们建议研究暗能量理论，并进一步发展它们，以及它们与暗物质理论的相互作用。我们提出的所有工作都涉及将尖端的理论思想和技术与严格的方法论和来自对撞机和宇宙学的最精确数据相结合。因此，我们认为，实现我们的目标将等同于对我们的领域具有持久价值的科学进步。

Particle physics has an ambitious goal : to understand our Universe at the most fundamental level. This means discovering all the elementary particles which are the ultimate building blocks of matter, and understanding the laws that govern their interactions. The current theory is known as the Standard Model of particle physics and it has enjoyed decades of remarkable success in explaining experimental data from all the high-energy particle collider experiments to date, including data from the current LHC at CERN. Yet it is also abundantly clear that there exists physics beyond the Standard Model which has eluded us and awaits discovery. For instance it is known that a large fraction of the material Universe is made up of "dark matter" which cannot be explained within the Standard Model. Our scientists are experts in Standard Model physics as well as in theories of particle physics beyond the Standard Model and their possible manifestation in colliders and cosmological data. We propose to exploit this expertise to maximise the prospects for discovery of new physics.One of the main routes to discovery involves confronting precise LHC data with equally precise theoretical predictions to look for deviations from the current theory, which would signal new physics. The landmark discovery of the Higgs boson, which deals with the origin of mass, offers an exciting avenue for further exploration. Often described as the last piece of the Standard Model jigsaw, the true nature of this particle is yet to become clear, and any deviation from the textbook Higgs boson could signal new physics. Our expertise in the theory of strong interactions (QCD) is critical for such studies at the LHC, which smashes together protons at high energies and where strong interactions are all pervasive. We specialise in the construction of algorithms which derive from QCD and lead to a full computer simulation of LHC collisions that can be directly compared to data. One of the proposed aims of our research is to design novel QCD based algorithms which improve the current state of the art in a variety of ways. We are also experts in the physics of "jets" which are formed in LHC collisions. In our proposal we aim to develop new methods that will enable us to distinguish jets produced by Standard Model particles from those arising from new particles, thereby enhancing the discovery potential of the LHC.If deviations from Standard Model expectations are seen in experimental data, we need to be able to interpret them in terms of theories of physics beyond the Standard Model. Our proposed research involves the continued construction of compelling models of new physics and investigating their signatures at the LHC. Another part of our research consists of actively pursuing some of the key questions that the Standard Model has left unanswered. One such question concerns the excess of matter over antimatter in our Universe and we propose to investigate directly related questions using the latest LHC data. Another direction involves searches for new particles, at colliders and elsewhere, that might be candidates for dark matter. Our scientists, with expertise in theories of dark matter, propose to study LHC data together with astrophysical observations and dedicated dark matter searches in order to discover the origin of dark matter. Yet another area where the Standard Model is inadequate is for explaining the "dark energy" that is responsible for the accelerated expansion of the Universe, for which there is overwhelming evidence. We propose to study dark energy theories and to develop them further, alongside their interplay with dark matter theories. All our proposed work involves combining cutting-edge theoretical ideas and techniques with rigorous methodology and the most precise data from colliders and cosmology. We thus believe that achievement of our goals will equate to scientific progress that shall be of lasting value to our field.