Experimental High Energy Particle Physics Research at UCL

实验粒子物理学研究的是极小的尺寸，或者相当于极高的能量。它告诉我们物理宇宙的基本性质，以及支配其发展的力量和定律，从大爆炸的第一时刻，到今天，直到遥远的未来。粒子物理学带来了许多革命性的想法，对我们看待自己和世界的方式产生了深远的影响。这些想法之所以具有强大的力量，原因之一是它们是基于对我们周围世界的实际科学观察，也就是实验。没有实验，科学就死了。能够达到这些极端能量和尺寸的实验在技术上非常具有挑战性。这些挑战包括设计可以在恶劣环境中工作的精密探测器，可以实现高能碰撞的粒子加速器，能够以非常小的“背景噪声”识别非常罕见的衰变的超灵敏探测器，每秒可以读出数百万条信息的高速电子设备，以及可以在全球分布式计算系统中分析数据的强大，灵活的软件。因此，活跃的粒子物理学活动的另一个结果是刺激技术发展和培训熟练开发和使用高技术的人员。这是一个“滚动补助金”，这意味着它涵盖了各种各样的粒子物理实验。滚动补助金支持高技能的研究和技术人员的基础，这使得UCL能够在实验物理学的最高水平的领导者。它提供了一定程度的职业保障，以及旅行和设备的钱。这也使该小组能够有效地培训博士生，事实上，我们正在竞标资助几名博士生。这项资助将支持的科学包括：-使用汉堡HERA对撞机的ZEUS探测器分析电子-质子碰撞，这告诉我们越来越多关于质子和光子的内部结构，以及将质子结合在一起的强大核力。- 在芝加哥的Tevatron对撞机上用CDF探测器分析质子-反质子碰撞，在那里对W玻色子（携带弱核力）进行精确测量，研究超重顶夸克，并寻找希格斯玻色子。- 来自芝加哥MINOS实验的中微子振荡分析。神秘的中微子曾经被认为是无质量的，但现在已知有质量- MINOS将对中微子的不同“味道”之间的混合进行最精确的测量。- 欧洲核子研究中心的ATLAS探测器投入使用，以及LHC的第一个数据分析。大型强子对撞机是第一个在“能量视界”之上运行的对撞机，在能量视界之上，弱力和电磁力是统一的。除了希格斯粒子，大型强子对撞机还可能发现超对称性、额外空间维度或其他我们想象不到的奇异现象。- NEMO-III实验的数据分析，这是一个在法国山下寻找“无中微子双β衰变”的超灵敏探测器。如果被发现，这一罕见的过程不仅将提供迄今为止对中微子质量的最佳测量，而且还将证明中微子与所有其他粒子不同，它是自己的反粒子。如果这是真的，这将为物理学在“大统一”尺度上提供一个很大的线索，在这个尺度上，所有的力都是（也许！）统一的我们还有其他中微子项目，拟议中的国际线性对撞机的工作，以及一些理论活动，所有这些都主要由其他赠款资助。这些项目因与滚动赠款同地而受益匪浅。所有这些项目都有助于智力令人兴奋的环境，这是UCL高能物理。

Experimental particle physics is about looking at extremely small sizes, or equivalently extremely high energies. It teaches us about the underlying nature of the physical universe, and the forces and laws that govern its development, from the first moments of the big bang, through to the present day, and far into the future. Particle physics has led to many revolutionary ideas, which have had a profound impact upon the way we think about ourselves and the world. One reason for the power of these ideas is that they are grounded in and tested by actual scientific observations of the world around us - that is, experiment. Without experiment, science is dead. Experiments capable of reaching these extremes of energy and 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, and 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 and the training of people skilled in the development and use of high technology. 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 and technical staff which makes UCL able to be a leader in experimental physics at the very highest levels. It provides a measure of career security, as well as travel and equipment money. This also allows the group to function effectively in the training of PhD students, and we are in fact bidding to fund several PhD students on this grant. The science this grant will support includes: - Analysis of electron-proton collisions using the ZEUS detector at the HERA collider in Hamburg, which is telling us more and more about the internal structure of the proton and the photon, and about the strong nuclear force which holds the proton together. - Analysis of proton-antiproton collisions with the CDF detector at the Tevatron collider in Chicago, where precision measurements of the W boson (which carries the weak nuclear force), studies of the super-heavy top quark, and a search for the Higgs boson are underway. - Analysis of neutrino oscillations from the MINOS experiment in Chicago. The mysterious neutrino was once thought to be massless but is now known to have mass - MINOS will make the most precise measurement of the mixing between the different 'flavours' of neutrino. - Commisioning of the ATLAS detector at CERN, and analysis of the first date from the LHC. The LHC is the first collider to operate above the 'energy horizon' above which the weak and electromagentic forces are unified. As well as the Higgs, the LHC may find supersymmetry, extra spatial dimensions, or other exotica we have not even imagined. - Analysis of data from the NEMO-III experiment, a super-sensitive detector under a mountain in France searching for 'neutrinoless double beta decay'. If found, this rare process would not only provide the best measurement by far of the neutrino's mass, but would also prove that unlike all other particles, the neutrino is its own antiparticle. If true, this would give a big clue to physics at the 'grand unification' scale, where all forces are (perhaps!) unified. We also have other neutrino projects, work on the proposed international linear collider, and some theoretical activities, all largely funded on other grants. These projects benefit greatly from being co-sited with the rolling grant. All these projects contribute to the intellectually exciting environment that is UCL high energy physics.