Beyond the Standard Model contributions to the nucleon electric dipole moment

超越标准模型对核子电偶极矩的贡献

• 批准号: 513989149
• 负责人: Professor Dr. Andrea Shindler
• 金额: --
• 依托单位: Institut für Theoretische Teilchenphysik und Kosmologie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/513989149?language=en
• 关键词: Beyond; Standard; Model; contributions; nucleon

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.

我们今天观察到的宇宙由物质而非反物质主导的原因仍然未知，它代表了现代物理学的重大问题之一。少量的电荷共轭-（C）和宇称-（P）对称性破缺必定推动了宇宙演化成我们今天观察到的样子。但神秘之处在于，已知的粒子物理学基本相互作用并不包含足够的 CP 破坏来解释我们今天观察到的不对称性。这一观察表明新物理学的存在包含了 CP 破坏的新来源。固有电偶极矩是CP破坏的标志，中子在实验和理论上都提供了理想的系统。经过65年的尝试，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测定。该项目的范围是根据新的CP破坏源引起的中子电偶极矩的基本原理提供精确的计算。为了实现这一目标，我们将非扰动地解决强相互作用理论，即量子色动力学（QCD），并将其定义在时空晶格上。为了克服过去阻碍此计算的技术和概念困难，我们将使用创新工具的组合：i）梯度流对 CP 破坏源进行重新归一化，以及 ii）新颖的 QCD 离散化、稳定威尔逊费米子，以控制连续谱极限和手性外推。这些新想法和技术发展的结合将能够精确计算源自新的CP破坏源的中子电偶极矩，从而为解释未来的实验测量提供理论结果，并为解释为什么宇宙目前由物质主导迈出关键一步。