Proposal for IPPP Consolidated Grant (2023-2026)

粒子物理研究在微观尺度上向我们揭示了物质的本质。当我们沿着低于原子长度的10^(-10)米的长度刻度向下移动，并超过原子核的长度刻度(10^(-15)米)，我们就进入了粒子物理学的领域。在这个领域，有三个公认的交互。首先，强相互作用负责结合夸克和胶子，产生质子、中子和其他统称为强子的粒子。第二，1983年在欧洲核子研究中心发现了电弱相互作用，负责从物质中辐射光子(光)和弱力载流子W玻色子和Z玻色子。第三，希格斯玻色子的相互作用。2012年，欧洲核子研究中心发现了希格斯玻色子。所有这些成分的相互作用由一种被称为标准模型(SM)规范理论的数学结构控制，该理论涉及电磁、弱和强相互作用。到目前为止，这一理论经受住了各种加速器带来的所有挑战，其中最新和最有活力的是大型强子对撞机。SM得到了证实--电磁和弱相互作用的统一被证明和测试到每毫升一份。强相互作用效应已经被测试到百分之一的水平。自2015年以来，大型强子对撞机(LHC)一直在以比以往更高的能量加速和碰撞质子，接近14TeV的设计能量。这种更高能量的探测器比以往任何时候的距离都要短得多。大型强子对撞机的高能范围也将允许详细研究希格斯玻色子和探索TeV尺度的物理。然而，大型强子对撞机实验比以往的任何粒子物理实验都要复杂得多。在TeV尺度上识别物理学的本质将需要实验者和理论家之间激烈的合作努力。在理论方面，需要对SM过程进行高精度的计算，以区分可能的新物理信号和SM背景。新物理的可能线索需要与SM之外的不同物理模型进行比较，以解开TeV尺度物理的底层结构。IPPP已经与英国和国际实验小组建立了密切的联系，并处于完美的地位，可以帮助英国最大限度地帮助理解大型强子对撞机数据。在规划和设计下一代粒子物理实验方面也做出了很大努力。IPPP将继续在评估物理潜力和未来加速器设计方面发挥作用。近年来，随着希格斯粒子的发现，标准模型得到了显著的证实，这是认识上的一次不朽的飞跃，可能是一个世纪才会发生一次。这一发现完善了标准模型，并为弱电对称破缺提供了第一个发现。然而，到目前为止，许多深层次的问题仍未被触及，令人着迷。这些问题从深刻的概念性问题到观察性问题，都是最有希望取得进展的机会。事实上，到目前为止，还没有观察到偏离标准模型的情况，似乎这些问题的许多更直接的解决方案并没有像我们想象的那样实现。因此，必须探索所有可能的途径和想法，采用一种多方面的方法，用从天体物理到直接探测到对撞机的所有可用证据来对抗理论期望。因此，IPPP将在可以用非对撞机实验回答的科学问题上加大研究力度。这包括寻找亮暗物质、轴子、研究随机引力波谱和非微扰现象。

Particle physics research informs us about the nature of matter on microscopic scales. As we step down the length scales below the length scale of the atom, 10^(-10) meters, and past the length scale of the atomic nucleus, 10^(-15) meters, we enter the realm of particle physics. In this realm, there are three well-identified interactions. First, the strong interactions are responsible for the binding of quarks and gluons to produce protons, neutrons, and other particles collectively called hadrons. Second, the electroweak interactions, responsible for the radiation of photons (light) from matter and the radiation of the weak force carriers, the W and Z bosons, were discovered at CERN in 1983. Third, the interactions of the Higgs bosons. The Higgs boson was discovered at CERN in 2012. The interactions of all of these ingredients are controlled by a mathematical structure known as the Standard Model (SM) gauge theory of electromagnetic, weak and strong interactions. This theory has so far withstood all the challenges posed by various accelerators, of which the latest and most energetic is the LHC. The SM is confirmed - with the unification of electromagnetism and weak interactions proved and tested to one part per mille. Strong interaction effects have been tested to the per cent level.Since 2015, the Large Hadron Collider (LHC) has been accelerating and colliding protons at much higher energies than ever before, close to the design energy of 14 TeV. This higher energy probes much shorter distance scales than ever before. The high energy reach of the LHC will also allow the detailed study of the Higgs boson and exploration of TeV scale physics. However, the LHC experiments are significantly more complex than any previous particle physics experiment. Identifying the nature of physics at the TeV scale will require intense collaborative efforts between experimentalists and theorists. On the theoretical side, high-precision calculations of SM processes are needed to distinguish possible signals of new physics from SM backgrounds. Possible hints of new physics need to be compared with different models of physics beyond the SM to disentangle TeV-scale physics' underlying structure. The IPPP has already established close connections with the UK and international experimental groups and is perfectly placed to help maximise the UK contribution to understanding the LHC data. There is also a strong effort in planning and designing the next generation of particle physics experiments. The IPPP will continue its role in assessing the physics potential and the design of future accelerators. The Standard Model received remarkable confirmation in recent years with the discovery of the Higgs, a monumental leap forwards in understanding that happens maybe once a century. That discovery completed the Standard Model and offered the first look at electroweak symmetry breaking. And yet many deep questions have so far remained tantalisingly untouched. These questions range from the profoundly conceptual to the observational, and they are the most promising opportunities for progress. Indeed so far, no deviation from the Standard Model has been observed, and it seems that many of the more straightforward solutions to these questions are not realised as we thought they might be. Therefore, all possible avenues and ideas must be explored, with a multi-faceted approach that confronts theoretical expectations with the whole gamut of available evidence from astrophysical to (in)direct detection to the collider. Consequently, the IPPP will increase its research endeavours in the science questions that can be answered with non-collider experiments. This includes the search for light dark matter, axions, the study of stochastic gravitational waves spectra and non-perturbative phenomena.