Search for the electric dipole moment of the neutron

电偶极矩（EDM）测量是粒子物理学（SM）标准模型之外最重要的物理研究之一。EDM是一个基本系统的属性，这在SM中是禁止的，但应该存在于大多数描述SM之外物理的可能模型中。在10-22 eV的能量分辨率下，寻找这个参数的实验是有史以来最精确的测量之一。由于其极其简单的组成，中子的EDM是一个非常突出的系统，并且已经排除或限制了许多新的物理模型。与我们的新实验，我们的目标是实现一个显着更好的灵敏度相比，最先进的。在慢中子物理学的Schwerpunktprogramm，我们已经准备好了一个设备来测量EDM的中子具有增强的灵敏度。该设备是同类设备中的第一个，为控制最关键的系统效应提供了独特的可能性。虽然该装置被放置在FRM-II，但它已经被建造成便携式和模块化，也考虑到FRM-II的UCN源的长时间延迟。2016年春天，劳厄-朗之万研究所（ILL）在国际上呼吁在目前最强大的现有UCN源的增强版本上进行旗舰实验。我们的设备赢得了这场比赛，这使我们能够通过将最好的系统学控制与最强的现有UCN源相结合来进行极具竞争力的实验。我们的目标是在本提案中对低10-27 ecm制度的灵敏度提高一个以上的数量级。我们的项目计划以最有效的方式使用SPP计划的投资：我们计划（i）使我们的设备适应ILL的新UCN源。我们计划只对现有硬件作出轻微改动;（ii）将电火花测量仪器的部分硬件由FRM-II移至ILL，将其设置在新的光束位置，并在新的环境中操作;（iii）用UCN表征仪器的性能，并进行电火花测量。(iv)与此同时，我们继续在TUM与外部磁屏蔽的研发，准备，测试和教育目的。在TUM保持在这样的环境中工作的能力是很重要的，我们对提案中列出的特定项目有明确的重点，我们的长期合作伙伴PTB也在本周提交了一份提案，这与我们的提案密切相关。我们知道我们不会在这个项目中完成EDM运行，但我们可以在本提案的范围内实际执行竞争性测量。长期战略，这是基于这一建议，也涉及重大的可能更新的硬件，提供卢瑟福实验室，使各种选项的长期战略，涉及ILL和FRM-II的同时。

Electric dipole moments (EDM) measurements are among the most important searches for physics beyond the standard model of particle physics (SM). An EDM is a property of a fundamental system, which is forbidden in the SM, but should be present in most possible models describing physics beyond the SM. With an energy resolution of 10-22 eV, the experiments searching for this parameter are among the most precise measurements ever performed. Due to its comparably simple composition, the EDM of the neutron is a very prominent system and has already ruled out or restricted many new-physics models. With our new experiment we aim to achieve a significantly better sensitivity compared to the state of the art.Within the Schwerpunktprogramm on slow neutron physics, we have prepared an apparatus to measure the EDM of the neutron with enhanced sensitivity. The apparatus is the first of its kind, providing a unique possibility to control the most critical systematic effects. Although the apparatus is placed at the FRM-II, it has been built portable and modular, also in view of the long delays of the UCN source at the FRM-II.In spring 2016, the Institut Laue-Langevin (ILL) made an international call for a flagship-experiment at the enhanced version of the currently strongest existing UCN source. Our apparatus won this competition, which enables us to perform a highly competitive experiment, by combining the best control of systematics with the strongest existing UCN source. We aim for a more-than-one order of magnitude improvement of the sensitivity to the low 10-27 ecm regime within this proposal.Our project plans to use the investments from the SPP program in the most efficient way: we plan to (i) adapt our apparatus for the new UCN source at ILL. We plan to make only minor adaptations to the existing hardware; (ii) move part of the hardware of the EDM apparatus from FRM-II to ILL, set it up at the new beam position and operate it in the new environment; (iii) characterize the performance of the apparatus with UCN and perform EDM measurements. (iv) In parallel we continue to work at TUM with the outer magnetic shield for R&D, preparation, test and education purpose. Maintaining the capability for work in such an environment at TUM is important and we have a well-defined focus on specific items listed in the proposal, enhanced by our long-term partner PTB, who submit a proposal also in this week, which is closely linked to our proposal.We are aware that we will not finish the EDM runs within this project, but we can realistically perform a competitive measurement within the scope of this proposal. The long-term strategy, which is based on this proposal, also involves major possible updates of the hardware, provided by Rutherford Lab, enabling various options for a long-term strategy involving ILL and FRM-II simultaneously.