Nuclear Physics Consolidated Grant 2023

如今，核物理学已经进入了第二个世纪，它仍然充满活力和活力。在过去的100年里，有大量的实验和理论研究导致了里程碑式的结果和发现，例如中子的发现，成功的原子核模型的发展，以及许多新的衰变模式的确定。核物理学的进步与粒子加速器的发展齐头并进，粒子加速器从能够加速光离子的普通静电机器开始，发展到能够将任何原子核加速到铀-238的现代加速器，每个核子的能量为10兆电子伏特或更高。现在已经有了使放射性离子加速的设备，人们正在努力提高放射性光束的强度、能量和纯度。尽管核物理学的研究活动丰富，而且这门学科也很成熟，但对原子核的完全理解仍然没有实现。仍有许多悬而未决的问题需要回答，我们将在我们的研究计划中加以解决。核物理学的技术和科学发展正在导致基础科学领域以外的应用-与核有关的概念现在被用于工业，医学和社会的许多领域，从而导致新的应用研究领域。我们在这一综合资助申请中的研究项目涵盖了对远离稳定原子核的结构、行为和性质的研究，以及对稳定原子核的集体行为的研究，这些研究仍然知之甚少。我们研究计划的主要部分之一是研究原子核的形状。众所周知，壳层被中子和质子填充的原子核是球形的，而壳层被部分填充的原子核则会变形。我们研究计划的主题之一是研究四极形核，其中核呈橄榄球形状。这种类型的核变形是普遍的，发生在核图的许多不同区域。一种更奇特的变形形式是当原子核呈现反射不对称的“梨”形时。这种八极变形在核图的局部区域最为突出，如轻锕系元素区（镭、钍、A~224的铀核）和钡-144附近的镧系元素。在我们的研究计划中，我们将对原子核中的八极变形进行全面的研究，重点是锕系和镧系区域，以及N=Z=56附近的富质子核。在核物理学之外对这些原子核有很大的关注，因为含有梨形原子核的原子是寻找原子电偶极矩的极好候选者。在过去的20年里，理论计算支持的实验观察表明，外来核的结构可能与接近稳定的核不同。众所周知的魔数序列，对应于核壳结构中的能量间隙，被认为是根据质子-中子比而变化的，被称为i型壳演化。事实上，ii型壳演化的最新进展表明，当核子从一个壳层激发到另一个壳层时，这种变化就会发生在原子核中。在我们的节目中，我们将研究原子核图上一系列原子核的壳演化，包括靠近双幻核Sn-100和Pb-208的原子核。我们研究计划的另一个方面是在多信使方法中研究原子核中的高能集体模式。后者为我们的研究提供了与核天体物理学相关的反应，其中将包括关注发生在恒星或核结构中的氢燃烧，这决定了爆炸天体物理场景中的过程，如ii型超新星。

Now well into its second century, the science of nuclear physics remains vibrant and active. Over the past 100 years, there has been a wealth of experimental and theoretical research that has led to milestone results and discoveries, such as the discovery of the neutron, the development of successful models of the nucleus, and the identification of numerous novel decay modes. Progress in nuclear physics has gone hand-in-hand with the development of particle accelerators, which started with modest electrostatic machines, capable of accelerating light ions, and resulting in modern day accelerators capable of accelerating any nucleus up to uranium-238, with energies of 10 MeV per nucleon or more. Facilities now exist that can accelerate radioactive ions, and there is effort being put into improving the intensities, energies, and purity of radioactive beams. Despite the wealth of research activity in nuclear physics, and the maturity of the subject, a complete understanding of the atomic nucleus has still not been achieved. There are still many open questions that need to be answered, which we will address in our research programme. Technological and scientific developments in nuclear physics are leading to applications outside of the areas of fundamental science - nuclear-related concepts are now used in many areas of industry, medicine, and society leading to new areas of applied research. Our programme of research in this Consolidated Grant application covers research into the structure, behaviour and properties of atomic nuclei that lie far from stability as well as collective behaviour in stable nuclei, which remains poorly understood. One of the main parts of our programme of research is the study of the shapes of atomic nuclei. It is well established that nuclei with filled shells of neutrons and protons are spherical, and nuclei with partially-filled shells can become deformed. One of the themes within our research programme will study quadrupole shaped nuclei, where the nucleus takes on a rugby-ball shape. This type of nuclear deformation is prevalent and occurs in many different regions of the nuclear chart. A more exotic form of deformation is when the nucleus takes on a reflection-asymmetric "pear" shape. Such octupole deformation is most prominent in localized regions of the nuclear chart, such as the light actinide region (radium, thorium, uranium nuclei with A~224) and lanthanides near barium-144. In our research programme, we will make a comprehensive study of octupole deformation in nuclei, focusing on the actinide and lanthanide regions, as well as the proton-rich nuclei near N=Z=56. There is significant attention on these nuclei from outside of nuclear physics since atoms containing pear-shaped nuclei are excellent candidates in which to search for an atomic electric dipole moment.Over the past 20 years, experimental observations, supported by theoretical calculations, have suggested that the structure of exotic nuclei may be different from those near stability. The well-known sequence of magic numbers, corresponding to energy gaps in nuclear shell structure, are thought to change depending on the proton-neutron ratio, known as type-I shell evolution. Indeed, the recent development of type-II shell evolution suggests such a change happens in a nucleus when exciting nucleons from one shell to another. In our programme, we will study the shell evolution in a range of nuclei across the nuclear chart, including the nuclei close to the doubly-magic nuclei Sn-100 and Pb-208. Another aspect of our research programme is a study of high-energy collective modes in nuclei, in multi-messenger approaches. The latter feeds into our research studying reactions relevant to nuclear astrophysics, which will include a focus on hydrogen burning that occurs in stars or nuclear structure determining processes in explosive astrophysical scenarios, like a type-II supernovae.