Next generation measurement of the electron electric dipole moment with heavy molecules.

我正在研究物质和反物质之间的关系。这种关系是当今物理学中最大的谜团之一。但在我解释为什么它是一个如此大的谜团之前，我应该先解释一下什么是反物质。我们周围的所有物质都是由质子、中子和电子组成的。这些亚原子粒子结合在一起形成原子，元素，然后这些原子结合在一起，形成我们周围看到的一切，固体、液体和气体。但这并不是亚原子故事的结束。当我们更仔细地观察时，我们发现除了质子、中子和电子之外，还有更多、更难以捉摸的亚原子粒子。我们在奇怪的地方发现了这些粒子：在宇宙射线阵雨中，在某些类型的核衰变中，在粒子对撞机中被粉碎的原子残留物中。物理学家试图解释这些粒子是如何相互关联的，以给粒子动物园带来秩序。他们取得了惊人的成功，提出了一种被称为标准模型的理论。这个标准模型为我们发现的数百个亚原子粒子带来了秩序，将它们分成具有规则模式的家族，以令人难以置信的精度预测它们的性质。这是二十世纪物理学的伟大成就之一。现在我可以解释什么是反物质了。标准模型最显著的特点之一是它将粒子排列成对。每个粒子都有一个带有相反电荷的伙伴，称为反粒子。这些反粒子就是我们所说的反物质。标准模型预测，这些反粒子应该遵守所有与正常粒子相同的规则。实验已经证实了这一点，粒子和反粒子的行为是非常对称的。适合一个人的东西就会适合另一个人。这就是最大的谜团！如果物质和反物质遵循相同的定律，如果物质和反物质的粒子成对出现，那么所有的反物质在哪里？我们预计，它的数量应该和正常物质一样多。但并没有。整个世界几乎完全由正常物质组成，只有微小的反物质痕迹。天文学家们一直在观察可见宇宙的边缘，即使到了那时，他们也只看到了物质，没有看到巨大的物质储备。所有的反物质都去哪了？我们正试图回答这个问题。我们希望通过寻找物质和反物质行为之间的微小差异来回答这个问题。这些微小的差异可能是导致反物质在宇宙演化的数十亿年中几近灭绝的原因吗？我们决定研究电子。我们可以把电子想像成一个带电荷的小球。我们要做的就是测量这个球是不是圆的。现在，这听起来可能与反物质的问题完全无关，但事实并非如此。我们有非常有力的证据告诉我们，除非电子是完全圆的，否则物质和反物质的行为不可能完全相同。因此，通过非常仔细地测量电子的形状，我们可以推断出一些关于反物质的性质。所有这些都不需要制造或使用任何实际的反物质-我认为这是非常优雅的！到目前为止，我们已经以令人难以置信的精度检查了电子的圆度：相当于测量地球的直径比一根头发的宽度更好。到目前为止，我们还没有看到非圆形的证据。我们计划在未来几年利用原子和分子物理学的一些最新发展，使我们的实验精确度提高1000倍。随着精度的提高，我们认为我们可能能够看到与完美圆度的微小偏差，并有望解释反物质的奥秘。

I'm doing research into the relationship between matter and antimatter. This relationship is one of the biggest mysteries in physics today. But before I get on to explaining why it's such a big mystery, I should explain a little about what antimatter is. All of the matter around us is made up of protons, neutrons and electrons. These subatomic particles combine together to make atoms, the elements, and then these atoms combine together to make everything we see around us, solid, liquid and gas. But this isn't the end of the subatomic story. As we've looked more carefully we've discovered that as well as protons, neutrons and electrons there are many more, much more elusive, subatomic particles. We've found these particles in odd places: in cosmic ray showers, some kinds of nuclear decays, and in the remnants of atoms that have been smashed in particle colliders. Physicists have tried to explain how these particles relate to one another, to bring order to the particle zoo. And they've been spectacularly succesful, coming up with a theory that is called the Standard Model. This Standard Model brings order to the hundreds of subatomic particles that we've discovered, sorting them into families with regular patterns, predicting their properties with incredible accuracy. It's one of the great triumphes of twentieth century physics. Now I can explain what antimatter is. One of the most striking features of the Standard Model is that it arranges the particles into pairs. Every particle has a partner with the opposite electrical charge called an anti-particle. These anti-particles are what we call antimatter. The Standard Model predicts that these anti-particles should obey all the same rules that normal particles do. Experiments have confirmed this, that particles and antiparticles behave in a very symmetric way. What goes for one goes for the other. This is the big mystery! If matter and antimatter obey just the same laws, if particles of matter and antimatter come in pairs, then where's all the antimatter? We would expect that there should be just as much of it as there is normal matter. But there's not. The whole world is made almost entirely of normal matter, with only tiny traces of antimatter. Astronomers have looked right to the edge of the visible universe and even then they see just matter, no great stashes of anitmatter. What happened to all the antimatter? It's this question that we are trying to answer. We hope to answer it by searching for tiny differences between the behaviour of matter and antimatter. Could these tiny differences be responsible for the near extinction of antimatter over the billions of years that the universe has been evolving? We've decided to study electrons. We can think of the electron as a little ball of electrical charge. What we do is measure whether this ball is round or not. Now, this might sound completely unrelated to the question of antimatter, but it's not. We have very strong evidence that tells us that unless electrons are _perfectly_ round, the matter and antimatter _can't_ behave in exactly the same way. So by making a very careful measurement of the electron's shape we can infer something about the nature of antimatter. All without having to make or use any actual antimatter - I think this is very elegant! So far we've checked the roundness of the electron to an incredible degree of precision: the equivalent would be measuring the diameter of the earth to better than the width of one human hair. And so far, we've seen no evidence of non-roundness. What we're planning on doing in the next few years is using some of the latest developments in atomic and molecular physics to make our experiment 1000 times more precise. With this increased precision we think we might be able to see a tiny deviation from perfect roundness and hopefully explain the mystery of the antimatter.