Beyond the Standard Model contributions to the nucleon electric dipole moment

为什么我们今天观察到的宇宙是由物质而不是反物质主导的，这个原因仍然未知，它代表了现代物理学的一个大问题。少量的电荷共轭(C)和宇称(P)对称性破缺必然推动了宇宙进化到我们今天所看到的样子。但令人不解的是，粒子物理学中已知的基本相互作用并没有包含足够的cp违反来解释我们今天观察到的不对称性。这一观测指向了包含cp违反新源的新物理学的存在。本征电偶极矩是cp违逆的标志，中子在实验和理论上都提供了一个理想的系统。经过65年的尝试，尽管我们仍然没有中子电偶极矩的实验证据，同时我们仍然缺乏精确的理论确定。这个项目的范围是从第一性原理提供一个精确的计算中子电偶极矩由新的cp违反源。为了达到这样的目标，我们将以非摄动的方式解决强相互作用理论，量子色动力学（QCD），在时空晶格上定义它。为了克服过去阻碍这一计算的技术和概念上的困难，我们将使用创新工具的组合：i)梯度流重新规范化cp违反源，ii)一种新的QCD离散化，稳定的威尔逊费米子，以控制连续体极限和手性外推。这些新想法和技术发展的结合将允许精确计算来自新的cp违反源的中子电偶极矩，从而为解释未来的实验测量提供理论结果，并在解释为什么宇宙目前由物质主导的关键一步。

The reason why the Universe we observe today is dominated by matter over antimatter is still unknown, and it represents one of the big questions of modern physics. A tiny amount of combined charge conjugation- (C) and parity- (P) symmetry breaking must have driven the evolution of the Universe to the way we observe it today. The mystery though is that the known fundamental interactions of particle physics do not contain enough CP-violation to explain the asymmetry we observe today. This observation points towards the existence of new physics containing new sources of CP-violation. Intrinsic electric dipole moments are a signature for CP-violation and the neutron provides an ideal system both experimentally and theoretically. After 65 years of attempts though we still have no experimental evidence of a neutron electric dipole moment and at the same time we still lack a precise theoretical determination. The scope of this project is to provide a precise calculation from first principles of the neutron electric dipole moment induced by new sources of CP-violation. To reach such a goal we are going to solve non-perturbatively the theory of strong interactions, Quantum Chromodynamics (QCD), defining it on a space-time lattice. To overcome the technical and conceptual difficulties that have hampered in the past this calculation, we will use a combination of innovative tools: i) the gradient flow to renormalize the CP-violating sources, and ii) a novel QCD discretization, Stabilized Wilson Fermions, to control continuum limit and chiral extrapolation. The combination of these new ideas and technical developments will allow a precise calculation of the neutron electric dipole moment stemming from new CP-violating source, thus providing the theoretical result for the interpretation of future experimental measurements and a key step in the explanation of why the Universe is currently dominated by matter.