Lattice investigations of strongly Interacting theories in the Standard Model and beyond.

普利茅斯大学理论粒子物理小组的研究项目集中在现代粒子物理的关键问题上。进行了两个方面的研究。在第一轮研究中，该小组参与了一场竞赛，目的是将实验测量的一个量的理论不确定性降低到一个被称为Muon反常磁矩的非凡精度。一种正在进行的电流实验，它测量电子的一个较重的表亲--µ子的小磁矩，目的是进一步减少实验误差。我们的理论计算将允许对在基本粒子水平上描述所有现象的理论进行进一步测试，该理论被称为粒子物理标准模型。如果实验结果和理论结果之间有统计学意义的更大差异，就会强烈暗示出标准模型之外的是什么，这将是一个重大发现。理论计算本身是一个重大的计算和理论挑战，因为对粒子反常矩的大量贡献，以及由于目标的高精度要求与实验精度相匹配。第二部分研究集中在探索可以用来解决标准模型的缺点的理论。考虑了两个主要方向。首先，该项目将探索一种有趣的可能性，即2012年发现的希格斯玻色子可能是由其他物质组成的复合粒子。所谓的复合希格斯模型使用的机制类似于将夸克限制在质子内的机制。质子是众所周知的粒子的最简单的例子，它不是基本粒子，而是复合粒子。另一个方向是探索和预测测试模型，这些模型可以解释宇宙中85%的物质，而这些物质不是目前基本粒子相互作用理论所描述的。多年来，已经收集了大量的实验证据，支持难以捉摸的“暗物质”的存在。最近对由两个相互碰撞的星系组成的“子弹状星团”的明显观察表明，暗物质与其自身有很强的相互作用。以如此强的相互作用为特征的理论与描述夸克相互作用并导致质子形成束束态的理论有相似之处，也与有可能以复合希格斯玻色子为特征的理论相似。所进行的计算将进一步约束动机良好的模型，从而有助于回答这样一个问题：“基本粒子是什么？”以及“暗物质的本质是什么？”

The research project of the theoretical particle physics group at theUniversity of Plymouth focuses on key issues of modern particlephysics. Two strands of research are pursued. In the first strand ofresearch, the group takes part in the race to decrease the theoreticaluncertainty on a quantity measured experimentally to an extraordinaryprecision called the anomalous magnetic moment of the muon. Anon-going current experiment that measures the small magnetic moment ofthe muon, a heavier cousin of the electron, aims at reducing furtherthe experimental errors. Our theoretical calculations will allowfurther tests of the theory that describes all phenomena at the levelof fundamental particles, called the Standard Model of particlephysics. A statistically significant larger difference between theexperimental and theoretical results would give strong hints to whatlies beyond the Standard Model and it would be a major discovery. Thetheoretical calculation itself represents a major computational andtheoretical challenge, due to the large number of contributions to themuon anomalous moment, and due to the target high accuracy required tomatch the experimental precision.The second strand of research focuses on exploring theories that canbe used to address the Standard Model's shortcomings. Two maindirections are considered. First, the project will explore the intriguingpossibility that the Higgs boson - discovered in 2012 - could be acomposite particle made of something else. The so called CompositeHiggs models use mechanisms similar to the one that is responsible forthe confinement of the quarks inside a proton. The proton is the simplest example ofa well-known particle, which is not fundamental, but composite. Anotherdirection is to explore and make predictions to test models that couldexplain the 85\% of the matter in the Universe that is not describedby the current theory of the interactions of elementary particles. Over theyears, a lot of experimental evidence has been gathered that support theexistence of the elusive "Dark Matter". Recent observations, notablyof the "Bullet Cluster" which consists of two colliding galaxiessuggest that Dark Matter interacts strongly with itself. Theories thatfeature such a strong interaction share similarities with the theorythat describes the interaction of quarks and lead to the formation ofthe proton as a bound state, and with the theories that are candidatesto feature a composite Higgs boson. The calculations performed willfurther constrain well motivated models and thereforecontribute to answer the question : "What are the fundamentalparticles?" and "What is the nature of dark matter?".