Nuclear deformation and symmetry breaking from an ab-initio perspective

原子核由质子和中子组成，位于原子的中心，是地球上所有元素的关键。了解质子和中子的排列方式对于了解我们的起源非常重要。核物理学最有力的测试之一是质子和中子的组织如何随着它们的数量变得不平衡而变化：当质子比中子多（或相反）时。为了了解这一点，世界各地正在开发世界级的实验设施。我的工作将集中在北美的两个新设施：加拿大的ARIEL和美国的FRIB。在这些设施中，将产生质子和中子数量差别很大的“外来”核。这将通过粉碎常见的原子核来实现，比如钙和氙的同位素，使它们分裂成我将研究的非常罕见的原子核。我的研究将有两个主要的重点：外来核的形状如何变化，以及质子和中子在原子核深处的相对行为。原子核可以包含几十个甚至几百个质子和中子。这些“核子”可以排列成许多形状，从足球到橄榄球、圆盘，甚至梨。因为这些形状需要所有的核子作为一个整体，它们是对我们理解的难以置信的强大考验——我们需要知道每一个质子和中子在做什么，才能理解它们的形状。我将测量这些奇异核的形状，帮助我们理解质子和中子在数量上非常不平衡时的行为。质子和中子在原子核内的相对行为是我要研究的另一个问题。作为核物理学家，我们从历史上发现，质子和中子在原子核内的行为实际上非常相似。这意味着一个有5个质子和4个中子的原子核和一个有4个质子和5个中子的原子核的行为非常相似，这是一个了不起的结果。我要研究的是，当我们向原子核中加入越来越多的质子和中子时，这种行为会有多好。这是一个非常重要的问题，原因有很多，这对我们理解恒星爆炸时元素是如何演变的有影响。核物理学是一个非常令人兴奋的领域，有许多悬而未决的问题。我将要使用的功能强大得令人难以置信的下一代设备将阐明其中的一些问题，而且很有可能在这个过程中开辟出一些令人兴奋的新问题。

The nucleus, consisting of protons and neutrons and lying at the center of the atom, is the lynchpin of all elements on Earth. Knowing how those protons and neutrons arrange themselves is important in order to understand our origins. One of the most powerful tests of nuclear physics is how the organization of the protons and neutrons changes as their numbers become imbalanced: when there are many more protons than neutrons (or the opposite). In order to understand this, world-class experimental facilities are being developed around the world. My work will focus on two new facilities based in North America: ARIEL in Canada, and FRIB in the United States. At these facilities "exotic" nuclei will be produced, with large differences in the numbers of protons and neutrons. This will be done by smashing together common nuclei, such as isotopes of calcium and xenon, causing them to break apart into the very rare nuclei which I will study. My research will have two primary focuses: how the shapes of exotic nuclei change, and how protons and neutrons behave relative to one another deep inside a nucleus. The nucleus can contain many tens or even hundreds of protons and neutrons. These "nucleons" can arrange themselves into many shapes, from footballs, to rugby-balls, disks, or even pears. Because these shapes require all of the nucleons to act as one they are incredibly powerful tests of our understanding - we need to know what every single proton and neutron is doing in order to understand the shape. I will measure these shapes for exotic nuclei, helping us understand how the protons and neutrons behave when they are very imbalanced in number. The question of how the proton and neutron behave relative to one another inside a nucleus is something else I will investigate. As nuclear physicists we have found historically that the proton and neutron actually behave very similarly inside the nucleus. This means that a nucleus with five protons and four neutrons behaves very similarly to a nucleus with four protons and five neutrons, which is a remarkable result. What I will investigate is how well this behaviour holds up as we add more and more protons and neutrons to the nucleus. This is a very significant question for a number of reasons, with implications for our understanding of how elements evolve when stars explode.Nuclear physics is a very exciting field, with a number of open questions. The incredibly powerful next-generation facilities that I will be using will shed light on a number of these questions and, in all likelihood, open up a number of new exciting ones in the process.