Experimental Particle Physics at UCL

实验粒子物理学寻求研究极小的尺寸，或相当于极高的能量。它实际上探测了宇宙大爆炸后不到一秒的宇宙状态。我们正在研究的这些独特条件最终使恒星、星系、行星和生命得以形成，并决定了宇宙将如何演变到遥远的未来。我们正在从基本力和粒子的角度研究物理宇宙的潜在本质。能够达到这些极端能量和尺寸的实验在技术上是非常具有挑战性的。挑战包括设计可以在恶劣环境中运行的精密探测器，可以实现高能碰撞的粒子加速器，能够识别非常罕见的衰变的超灵敏探测器，非常小的“背景噪声”，高速电子设备，每秒可以读取数百万条信息，以及强大的，灵活的软件，可以分析世界各地分布式计算系统中的数据。因此，活跃的粒子物理活动的另一个后果是刺激技术发展，培训熟练的人在开发和使用创新技术和提高工业制造能力。这是一笔“滚动拨款”，这意味着它涵盖了各种各样的粒子物理实验。滚动拨款支持高技能的研究和技术人员的基础，使伦敦大学学院成为实验物理学最高水平的领导者。它提供了一定程度的职业保障，以及旅行和设备费用。这也使该小组能够有效地培训博士生和年轻的博士后研究人员。至关重要的是，这笔拨款将支持的科学进步是建立在实验观察的基础上并将得到实验观察的检验。这笔拨款将支持的科学包括：-通过寻找新的基本粒子（如希格斯玻色子）来理解粒子质量的机制；使用欧洲核子研究中心（CERN）的大型强子对撞机（LHC）的ATLAS探测器详细检查W玻色子（负责弱核力的粒子）在最高能量下的相互作用；通过使用Tevatron对撞机的CDF探测器非常精确地测量W玻色子的质量。-理解为什么我们生活在一个由物质主导的宇宙中，只有少量的反物质成分，这与大爆炸后物质和反物质等量共存的条件不一致。我们将详细研究中微子的性质，中微子是一种稳定的、不带电的、几乎没有质量的粒子，在放射性衰变和不稳定粒子的衰变中释放出来。这项研究是在MINOS， NEMO-III和最终的SuperNEMO（我们正在建造）实验中进行的，这些实验正在寻找中微子改变其身份的罕见过程和释放两个电子而不释放中微子的罕见β衰变过程。-通过使用HERA对撞机上的ZEUS探测器测量质子的内部结构，了解强核力的本质。-寻找极高能量的现象，这有助于定义一个更基本的理论，统一20世纪物理学的两大支柱：爱因斯坦的广义相对论和量子力学。我们正在寻找超高能中微子与南极冰的相互作用，使用ANITA实验和研发实验来寻找μ子（一种重电子类型的粒子）自发转化为电子的极其罕见的过程。其中一些工作是由其他赠款资助的，但得到了这项滚动赠款支持的技术专长的支持。对伦敦大学学院高能物理小组的技术基础和年轻研究人员的发展的连续性和支持对科学的进步及其带来的好处至关重要。

Experimental particle physics seeks to study extremely small sizes, or equivalently extremely high energies. It in effect probes the conditions that existed in the universe a fraction of a second after the Big Bang. These unique conditions that we are studying ultimately allowed stars, galaxies, planets & finally life to form & dictate how the universe will evolve far into the future. We are studying the underlying nature of the physical universe in terms of fundamental forces & particles. Experiments capable of reaching these extremes of energy & size are very technically challenging. The challenges include devising precision detectors which can operate in hostile environments, particle accelerators which can achieve high energy collisions, super-sensitive detectors capable of identifying very rare decays with very small 'background noise', high-speed electronics which can read out millions of pieces of information per second, & robust, flexible software which can analyse the data in a distributed computing system all over the world. Thus another consequence of an active particle physics activity is a stimulation of technological developments, the training of people skilled in the development & use of innovative technology & improvements in industrial manufacturing capability. This is a 'rolling grant', which means that it covers a broad variety of particle physics experiments. The rolling grant underpins the base of highly skilled research & technical staff allowing UCL to be a leader in experimental physics at the very highest levels. It provides a measure of career security, as well as travel & equipment money. This also allows the group to function effectively in the training of PhD students & young post-doctoral researchers. Crucially, the scientific advances that this grant will support are grounded in & will be tested by experimental observations. The science this grant will support includes: - Understanding the mechanism that gives particles mass by searching for new fundamental particles such as the Higgs boson & examining in detail the interactions of W bosons (the particles responsible for the weak nuclear force) at the highest energies using the ATLAS detector at CERN's LHC & by measuring very precisely the mass of the W boson using the CDF detector at the Tevatron collider. - Understanding why we live in a universe that is dominated by matter with only a tiny anti-matter component which is at odds with the conditions immediately following the Big Bang when matter & antimatter co-existed in equal amounts. We will study in detail the properties of the neutrino, which is a stable, uncharged, almost massless particle released in radioactive beta decays & decays of unstable particles. The study is performed at the MINOS, NEMO-III & ultimately SuperNEMO (which we are building) experiments that are searching for rare processes where neutrinos change their identity & for rare beta decay processes releasing two electrons & no neutrinos. - Understanding the nature of the strong nuclear force through measurements of the internal structure of the proton using the ZEUS detector at the HERA collider. - Searching for phenomena at extremely high energy which can help to define a more fundamental theory that unifies the twin pillars of 20th century physics: Einstein's theory of General Relativity & Quantum Mechanics. We are searching for the interaction of ultra-high energy neutrinos with the Antarctic ice using the ANITA experiment & R&D towards experiments searching for the exceedingly rare process whereby a muon (a heavy electron type particle) spontaneously converts into an electron. Some of this work is funded on other grants but is underpinned by the technical expertise that is supported by this rolling grant. Continuity & support for the technical base in the UCL High Energy Physics Group & for the young researchers to develop is vital to progress the science & the benefits that it brings.