Edinburgh Nuclear Physics Group Consolidated Grant Proposal

我们今天观察到的化学元素大多是从古代恒星爆炸的灰烬中产生的。这类事件中最壮观的是超新星。借助灵敏度非常高的现代望远镜，我们可以研究从遥远的超新星喷出的物质的化学丰度，并与我们太阳系中发现的丰度进行比较。理解极端的天体物理事件如何产生今天在望远镜和陨石中观察到的稳定元素，关键取决于不稳定的外来核的性质，这些核最初存在于极端高温和密度的恒星环境中，元素在其中锻造，最终衰减回到稳定状态。我们很幸运，现在我们有了现代加速器和探测器系统的工具，第一次研究这些奇异的核及其反应。奇异核可以表现出显著的性质，与自然界中发现的同位素相比，具有不同的微观壳层结构。在原子核存在的极端，即所谓的滴线，原子核可以通过发射组成原子核的核子而衰变。这是一个非常基本的量子隧穿过程，其速率对核表面的形状非常敏感。一些原子核可以拥有不止一种稳定的形状，这种现象被称为形状共存，这代表了一个独特的实验室来研究形状对量子隧穿的影响。在中子发射的情况下，所谓的1-中子放射性还没有被发现，虽然它可能是在实验中观察到的非常丰富的中子核，如在超新星爆炸产生的区域的奇异亚稳态的衰变。虽然核子在原子核中的集合体有着令人瞩目的行为，但关于核子本身是如何形成的，还有许多问题有待解决。这是一个非常令人兴奋的领域，自然会引起人们对夸克在核子本身和其他束缚夸克系统中的作用的思考。在未来的十年里，基于量子染色体动力学（QCD）等现代理论，人们有可能对所涉及的过程有更基本的了解。这样的理论表明存在着被称为胶球和夸克-胶子混合体的未被发现的粒子;我们将在未来的实验中寻找这些粒子。爱丁堡集团利用其世界领先的专业知识开发先进的硅条探测器和仪器系统，用于主要国际加速器设施的关键科学实验，由集团成员，英国科学家和国际合作者使用。这是科学开发新一代放射性离子束设施的重要技术，也是英国与英国公司联合开发产品的世界领先领域。

The chemical elements we observe today were mostly created from the ashes of ancient stellar explosions. The most spectacular events of this type are supernovae. With very high sensitivity modern telescopes we can study the chemical abundances of material ejected from distant supernovae and compare with those abundances found in our own solar system. Understanding how extreme astrophysical events produce the stable elements observed today in telescopes, and meteorites, depends critcially on the properties of unstable exotic nuclei which were originally present in the extreme high temperature and density stellar environments in which the elements were forged, before ultimately decaying back to the stability. We are lucky that now we have the tools with modern accelerators and detector systems to study these exotic nuclei and their reactions for the first time. Exotic nuclei can exhibit remarkable properties, possessing different microscopic shell structure compared with isotopes found in nature. At the extremes of nuclear existence, known as the drip-lines, nuclei can decay by emitting their constituent nucleons. This is a very basic quantum tunneling process, whose rate is remarkably sensitive to the shape of the nuclear surface. Some nuclei can possess more than one stable shape, a phenomenon known as shape coexistence, which represents a unique laboratory to study the influence of shapes on quantum tunnelling. In the case of neutron emission, so-called 1-neutron radioactivity has yet to be discovered at all, although it might be observable in experiments from the decay of exotic metastable states in regions of very neutron-rich nuclei, such as are produced in supernovae explosions. While assemblies of nucleons in nuclei behave in remarkable ways, there are also many questions about how the nucleons themselves are formed.This is a very exciting field that naturally leads to consideration of the roles of quarks inside the nucleons themselves, and other bound quark systems. Exciting possibilities exist in the coming decade to obtain a more fundamental understanding of the processes involved ,based on modern theories such as Quantum Chromo Dynamics (QCD). Such theories suggest the existence of remarkable undiscovered particles called glueballs, and quark-gluon hybrids; we will search for these in future experiments. The Edinburgh Group uses its world-leading expertise to develop advanced silicon strip detector and instrumentation systems that are used for key scientific experiments at major international accelerator facilities, by group members, UK scientists and International collaborators. This is a vital technology for the scientific exploitation of new generation Radoactive Ion Beam facilities, and is a field where the UK has a world lead using products jointly developed with UK firms.