Dark matter detection probe

暗物质的存在及其组成是现代物理学中最令人着迷的谜团之一。尽管天文学和宇宙学证据表明暗物质存在于多个来源，但除了引力之外，它的相互作用仍未被发现。在标准模型的各种扩展中激发的光赝标量玻色子是暗物质的可行候选者。其中，类轴子粒子（ALP）通过不同的入口与标准模型粒子相互作用，例如它们通过所谓的梯度耦合作用于核自旋。如果星系中的暗物质由光赝标量玻色子组成，则该场可以描述为康普顿频率的经典振荡，即频率与ALP的质量成正比。这样，暗物质就像振荡磁场一样作用于核自旋。当放置在高达14.1 t的可调谐磁场中时，定制的核磁共振探头将能够在70 MHz至600 MHz的频率范围内搜索ALP暗物质，并具有最大（自旋投影噪声限制）灵敏度。该磁铁不属于Großgerät提案的一部分。暗物质的特征类似于振荡磁场，因此实验室中存在的实际电磁场需要通过磁屏蔽来抑制，这是所要求设备的一部分。

The existence of dark matter and its composition is one of the most intriguing mysteries of modern physics. Although astronomical and cosmological evidence for dark matter exists from multiple sources, its interactions, gravity aside, remain undetected. Light-pseudoscalar bosons, motivated in various extensions of the Standard Model are viable candidates for dark matter. Among them, axion-like particles (ALP) interact with standard model particles via different portals, for example, they act on nuclear spins via a so called gradient coupling. If dark matter in the galaxy is composed of light pseudoscalar bosons, the field can be described as a classical oscillation at the Compton frequency, i.e. the frequency is proportional to the mass of the ALP. This way, dark matter acts on the nuclear spins as an oscillating magnetic field. The custom-made NMR probe head will be capable to search for ALP dark matter in a frequency range from 70 MHz to 600 MHz with maximal (spin-projection-noise limited) sensitivity when placed in a tunable magnetic field of up to 14.1 T. This magnet is not part of this Großgerät proposal. The dark matter signature is similar to an oscillating magnetic field, so that actual electromagnetic fields present in the laboratory need to be suppressed via magnetic shielding, which is part of the requested device.