DARK MAtter for Precision experiments (DARKMAP)

我们对宇宙内部运作的最好理解是暗物质贡献了宇宙总质量的80%，在所有天文尺度上塑造了宇宙的形态。然而，从基本粒子的角度来看，暗物质的组成仍然是一个谜，所有试图通过测量或直接观察来解决它的尝试都失败了。已经建立的实验集中在寻找暗物质，暗物质在地下深处的实验室中散射出重原子，假设它的行为像缓慢移动的粒子。这种类型的暗物质被称为弱相互作用大质量粒子（WIMP），它的质量是质子质量的倍数。对于低于碳原子质量的暗物质，缓慢移动的wimp的动量下降到这些实验中使用的重核的反冲阈值以下，并且无法再检测到。如果暗物质轻得多，它的性质就会从根本上不同，而且它更应该被描述为一种均匀的流体状物质，而不是一团大质量粒子。在这种情况下，寻找弹性散射的实验是完全不敏感的。这种非常轻的暗物质表现得更像是一种新的力，对电子和原子核的作用非常弱，或者影响它们的自旋。在这种情况下，预期的效应很小，只有在对基本常数和相互作用进行极其精确的测量时才能观察到。这个项目是一个真正的多学科的努力，可以用高精度的原子物理实验来寻找暗物质。在过去的几十年里，许多这样的实验取得了巨大的进展，它们的灵敏度提高了许多数量级。这些高精度的实验可以潜在地测量光和非常轻的暗物质相互作用所产生的非常微小的影响。这种暗物质在宇宙中产生的理论机制是有帮助的，因为它预测了共振增强的随时间变化的信号，如果实验可以被设计成能够捕捉到的话。根据具体的相互作用，一个专门的或多种实验可能是正确的策略。为了回答这个问题，将开发一个一致的理论框架，考虑到描述高能暗物质所必需的量子场论的复杂结构。尽管与对撞机实验或甚至一些天体物理过程相比，高精度实验是在相当低的能量下进行的，但这些计算对于正确推导这些实验的观测值和观测值之间的相关性是必要的。该框架进一步使不同的实验方法具有可比性，现有的限制可用于优化未来的实验。有了这个，我们可以与全英国的原子物理学家合作，设计一个实验项目，利用高精度实验的未开发潜力来寻找和潜在地发现暗物质。

Our best understanding of the inner working of the Universe demands that Dark Matter contributes about 80% of the total mass of the Universe, shaping its form at all astronomical scales. However, the composition of Dark Matter in terms of fundamental particles remains a puzzleand all attempts to solve it through measurements or direct observation have failed to date.Established experiments have focussed on searches for Dark Matter that scatters off heavy atoms in deep underground labs, assuming it behaves like slowly moving particles. This type of Dark Matter is called Weakly Interacting Massive Particle (WIMP) and its mass is a multiple of the proton mass. For Dark Matter masses below the mass of a Carbon atom the momentum of the slowly moving WIMPs drops below the recoil threshold of the heavy nuclei used in these experiments and it cannot be detected anymore. If Dark Matter is much lighter, its properties are fundamentally different, and it would be better described as a homogeneous fluid-like substance instead of a cloud of massive particle. Experiments searching for elastic scattering are entirely insensitive in this case. This very light Dark Matter behaves more like a new force acting very weakly on electrons and nuclei or affecting their spin. In this case the expected effects are tiny and can only be observed in extremely precise measurements of fundamental constants and interactions.This project is a truly multidisciplinary effort to enable the search for dark matter with high-precision atomic physics experiments. Many of these experiments have made enormous progress during the last decades, increasing their sensitivity by many orders of magnitude. These high-precision experiments can potentially measure the very minute effects exerted by interactions of light and very light dark matter. The theoretical mechanism underlying the production of this type of dark matter in the universe helps, because it predicts resonantly enhanced time-dependent signals, if the experiment can be designed to pick it up. Depending on the specific interaction, one dedicated or a variety of experiments might be the right strategy.In order to answer this question a consistent theoretical framework will be developed taking into account the complex structure of quantum field theories necessary to describe dark matter at high energies. Even though high-precision experiments are performed at rather low energies compared to collider experiments or even some astrophysical processes these calculations are necessary to correctly derive observables and correlations between observables for these experiments. This framework further makes the different experimental approaches comparable and existing limits can be used to optimise future experiments. With this in hand we can collaborate with atomic physicists throughout the UK to design an experimental programme exploiting the untapped potential of high-precision experiments to search for and potentially discover dark matter.