Birmingham Nuclear Physics Group Consolidated Grant

原子核最近刚过一百周年纪念。在这段时间里，对原子核及其结构的理解有了很大的发展。然而，也许令人惊讶的是，仍然不可能以足够的精度计算它们的结构。基本的局限性不仅在于原子核是一个多体的物体，复杂性是一个自然的结果，而且相互作用从根本上说还有待理解。正是这种相互作用产生了各种复杂的核结构，从团簇到晕，从球形到变形，从稳定到不稳定。为了取得更大的进展，人们必须理解核强相互作用是如何从亚核子水平上出现的，在亚核子水平上，夸克和胶子是适当的自由度。手征有效场论的自治领领域是从量子色动力学（QCD）水平增长核力。这是一系列的方法之一，它希望将导致理解原子核的第一原则（从头算）。伯明翰核物理小组的研究跨越了从QCD到核子的领域，并试图回答该主题的一些核心挑战。通过在实验室中产生的最高能量的原子核碰撞，该小组正在探索夸克胶子等离子体（QGP）。这是一种物质状态，当碰撞中的能量很高时，核子（质子和中子）融化成夸克和胶子。这被认为是大爆炸后瞬间物质的状态。这些条件是在实验室中短暂创造的，挑战是在物质解离之前在这个阶段对其进行探测。伯明翰小组是欧洲核子研究中心大型强子对撞机ALICE合作的一部分，并开发了复杂的触发器，它在形成QGP的数百万次碰撞中选择关键事件。通过我们的科学领导，我们已经能够感受到QGP的性质。目前赠款的挑战是超越相当初步的理解，以提供其属性的精确表征。这涉及到粒子从QGP发射时的详细测量，例如测量它们穿过等离子体时的生存概率。第二部分是从夸克尺度到原子核尺度的研究。原子核的从头计算是具有挑战性的，对许多原子核来说，极限接近于质量12。因此，大部分的焦点都落在了碳12上。伯明翰小组领导了对这种原子核和一种特殊的量子态--霍伊尔态--的实验理解的发展。这种奇特的状态不仅被认为是由三个α粒子构成的，而且与恒星中碳的合成有关。如果国家不存在，有机（碳基）生命也不会存在。了解它的结构是人类生存的基础。该小组不仅对这一理解做出了重大贡献，而且我们正在探索整个轻核序列中的α-集群相关性。理解这些相关性是检验从头算模型和我们理解核力的关键。该小组将进行一系列精确的测量，以提供最好的核模型的严格测试到目前为止。目前的应用是一个潜在的高影响力的贡献，我们对核和强子物质的理解的发展。

The atomic nucleus has recently seen its centenary. Over this time understanding of nuclei and their structure has evolved considerably. However, and perhaps surprisingly it is still not possible to calculate their structure with sufficient accuracy. The fundamental limitation is not only that the nucleus is a many body object, and the complexity that is a natural consequence, but the interaction is fundamentally yet to be understood. It is this interaction which generates all sorts of complex nuclear structures from clustering to halos, from spherical to deformed, from stable to unstable. In order to make more progress one has to understand how the nuclear strong interaction emerges from that at the sub nucleonic level, where quarks and gluons are the appropriate degrees of freedom. Growing the nuclear force from the Quantum Chromodynamic (QCD) level is the dominion of chiral effective field theory. This is one of a range of approaches which it is hoped will lead to understanding nuclei from first principles (ab initio). The Birmingham Nuclear Physics group's research spans the territory from the QCD to nucleonic and seeks to answer some of the central challenges of the subject. Through the collisions of nuclei at the highest possible energies yet created in the laboratory the group is exploring the quark-gluon plasma (QGP). This is a state of matter created when the energy in the collision is so high that the nucleons (protons and neutrons) melt into the quarks and gluons. This is believed to be precisely the phase of matter an instant after the big bang. These conditions are created in the laboratory for a fleeting moment and the challenge is to probe the matter in this phase before it dissociates. The Birmingham group are part of the ALICE collaboration at the LHC in CERN and have developed the sophisticated trigger, which selects key events in the millions of collisions in which the QGP is formed. Through our scientific leadership we have been able to get a feeling for the properties of the QGP. The challenge for the present grant is to go beyond the rather rudimentary understanding to provide a precise characterisation of its properties. This involves detailed measurements of particles as they are emitted from the QGP, for example measuring their survival probability as they cross the plasma. The aim to to reach a detailed understanding of this state of hadronic matter.The second strand reaches from the quark scale to the scale of nuclei. The ab initio calculations of nuclei are challenging and for many of them the limits lie close to mass 12. As a result much of the focus has fallen on carbon-12. The Birmingham group has led the development of the experimental understand of this nucleus and one particular quantum state - the Hoyle-state. This rather exotic state is not only believed to be constructed from three alpha-particles, but to be associated with the synthesis of carbon in stars. If the state did not exist nor would organic (carbon-based) life. Understanding its structure is fundamental to human existence. Not only has the group made a significant contribution to this understanding, but we are exploring the alpha-cluster correlations in a whole sequence of light nuclei. It is understanding these correlations which is key to testing the ab initio models and our understanding of the nuclear force. The group will perform a series of precision measurements to provide stringent tests of the best nuclear models to-date.The present application is a potentially high impact contribution to the development of our understanding of nuclear and hadronic matter.