The Lancaster, Manchester, Sheffield Consortium for Fundamental Physics: Particle Physics, From the Universe to the LHC

粒子物理学是关于理解自然的基本组成部分及其相互作用的。多年来，物理学家已经发展出粒子物理学的标准模型，它在描述非常广泛的自然现象方面非常成功，从光如何工作和原子为什么形成到恒星内部的复杂工作以及大爆炸后最初几分钟的原子核合成。然而，我们知道标准模型并不是故事的全部，因为它留下了许多未解答的问题。我们的建议集中在这些未解的问题上，以及科学家们希望在未来几年利用大型强子对撞机（LHC）等实验或普朗克卫星等观测来解决这些问题的方式。在LHC发现希格斯玻色子是我们寻求理解质量起源的一个重要里程碑。然而，这当然不是故事的全部。LHC实验正在努力测量他们发现的粒子的性质。他们还在寻找新的粒子，比如超对称性预测的粒子。如果超对称性被发现，那么它提供了解释暗物质起源的希望，暗物质构成了已知存在于宇宙中的物质的很大一部分。我们联盟的科学家将探索超对称性和暗物质理论。我们将使用来自LHC等实验的数据来确定数据允许的超对称性的许多可能变体中的哪一个，并提出在实验中探索这些模型的新方法。LHC产生的任何“新物理学”都将是两个质子相互撞击的结果，这是一个非常复杂的环境，通常与其他粒子的“喷流”有关。我们联盟的成员将探索如何利用这些喷流来更多地了解相关的新物理学：我们越了解新物理学发生的环境，我们就越能够了解新物理学本身。这是一项复杂的工作，通常需要计算机模拟粒子碰撞。我们的成员都是模拟方面的专家，并且有计划如何使模拟更加准确，如果我们要充分利用来自LHC的激动人心的数据，这是必要的。粒子物理学的标准模型在解释宇宙的早期历史时也是不够的，当它是热的和密集的。现在有非常有力的证据表明，历史开始于一个加速膨胀的时代，称为通货膨胀。我们是通货膨胀及其后果的专家。暴胀使宇宙变得毫无特色，除了微小的量子波动，导致宇宙中物质和能量的密度随位置而变化。这些最初很小的变化发展成为可观察到的效应。效应之一是夜空中数十亿个星系的形成。另一种方法是在宇宙微波背景辐射（CMB）上留下一个微小的印记，宇宙沐浴在微波辐射的微弱嗡嗡声中。2009年发射的普朗克卫星正在对CMB进行细致的研究。我们站在解释普朗克数据的最前沿，希望能确定早期宇宙的各种理论中哪些被排除在外，哪些仍然可行。标准模型的缺陷更进一步，因为它没有解释普通物质的数量，甚至没有解释普通物质的存在。我们的科学家将利用这一点来限制标准模型之外的可能物理学，为此，他们需要在暴胀结束后不久掌握宇宙的动力学。最后但并非最不重要的是，我们希望更好地理解驱动宇宙当前和未来加速的神秘“暗能量”：一种可能性是，这是因为爱因斯坦的引力理论不太正确，这是我们将要探索的东西。

Particle physics is all about understanding the elementary building blocks of nature and their interactions. Over the years, physicists have developed the Standard Model of particle physics, which is extremely successful in describing a very wide range of natural phenomena from things as basic as how light works and why atoms form through to the complicated workings inside stars and the synthesis of nuclei in the first few minutes after the Big Bang. However, we know that the Standard Model is not the whole story for it leaves many questions unanswered. Our proposal focuses on these unanswered questions and the way that scientists hope to address them in the coming years using experiments like the Large Hadron Collider (LHC) or observations like those that will be made using the Planck satellite.The discovery at the LHC of a Higgs boson is a major milestone in our quest to understand the origin of mass. It is certainly not, however, the whole story. The LHC experiments are working hard to measure the properties of the particle they have discovered. They are also searching for new particles such as those predicted by supersymmetry. If supersymmetry is discovered then it offers the hope to explain the origin of the Dark Matter that makes up a large fraction of the material that is known to exist in the Universe. The scientists in our consortium will explore the theory of supersymmetry and dark matter. We will use data from experiments like the LHC to identify which of the many possible variants of supersymmetry are allowed by the data and to suggest new ways to explore those models in experiments. Any "new physics" produced at the LHC will be produced as a result of smashing two protons into each other, a very complicated environment, usually in association with "jets" of other particles. Members of our consortium will explore how we can make use of these jets to learn more about the associated new physics: the better we understand the environment in which new physics occurs, the more we are able to learn about the new physics itself. This is a complicated business that often necessitates computer simulations of particle collisions. Our members are experts in these simulations and have plans on how the make them more accurate, which is necessary if we are to make the most of the exciting data from the LHC.The Standard Model of particle physics is also insufficient when it comes to explaining the early history of the Universe, when it was hot and dense. The evidence is now very strong that the history began with an era of accelerating expansion, called inflation. We are experts on inflation and its consequences. Inflation makes the Universe featureless, except for tiny quantum fluctuations that cause the density of matter and energy in the Universe to vary with position. These initially small variations grow to become observable effects. One effect is the formation of the billions of galaxies that populate the night sky. Another is to leave a tiny imprint on the cosmic microwave background radiation (CMB), a faint hum of microwave radiation in which the Universe is bathed. The CMB is being studied in exquisite detail by the Planck satellite, which was launched in 2009. We are at the forefront of interpreting the Planck data in the hope of pinning down which of the various theories of the early universe are ruled out and which remain viable. The deficiencies of the Standard Model extend still further for it does not explain the amount nor even the existence of ordinary matter. Our scientists will use this to constrain possible physics beyond the Standard Model and to do that they need to master the dynamics of the Universe shortly after the end of inflation. Last but not least, we hope to understand better the mysterious "Dark Energy" that drives the current and future acceleration of the Universe: one possibility is that it is because Einstein's theory of gravity is not quite right and that is something we will explore.