Super-Nyquist ultralight dark matter searches with broadband atom gradiometers
Super-Nyquist ultralight dark matter searches with broadband atom gradiometers
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DOI：
10.1103/physrevd.108.083016
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发表时间：
2023-06
影响因子：
5
通讯作者：
L. Badurina;A. Beniwal;C. McCabe
中科院分区：
文献类型：
--
作者：
L. Badurina;A. Beniwal;C. McCabe
原子梯度仪已经成为标量超轻暗物质（ULDM）候选者的引人注目的宽带探针，其振荡频率约为10 ^{-2}$ Hz至10^3 $ Hz。频率大于$\sim 1$ Hz的ULDM信号超过原子梯度仪的预期奈奎斯特频率，因此受到混叠和相关现象的影响，包括信号折叠和频谱失真。为了便于发现超奈奎斯特ULDM信号，在这项工作中，我们研究了这些影响的参数重建使用一个强大的基于似然的框架。我们证明，只要实验频率分辨率大于ULDM信号线宽，就可以实现ULDM参数的准确重建。值得注意的是，由于频率相差采样频率的整数倍的ULDM候选者在相同的混叠频率下被识别，我们的发现分析恢复了参数空间中的离散岛。我们的研究代表了在暗物质直接探测的背景下对混叠的第一次全面探索，并为原子梯度仪增强ULDM探测策略铺平了道路。
Atom gradiometers have emerged as compelling broadband probes of scalar ultralight dark matter (ULDM) candidates that oscillate with frequencies between approximately $10^{-2}$ Hz and $10^3$ Hz. ULDM signals with frequencies greater than $\sim 1$ Hz exceed the expected Nyquist frequency of atom gradiometers, and so are affected by aliasing and related phenomena, including signal folding and spectral distortion. To facilitate the discovery of super-Nyquist ULDM signals, in this work we investigate the impact of these effects on parameter reconstruction using a robust likelihood-based framework. We demonstrate that accurate reconstruction of ULDM parameters can be achieved as long as the experimental frequency resolution is larger than the ULDM signal linewidth. Notably, as ULDM candidates whose frequencies differ by integer multiples of the sampling frequency are identified at the same aliased frequency, our discovery analysis recovers discrete islands in parameter space. Our study represents the first comprehensive exploration of aliasing in the context of dark matter direct detection and paves the way for enhanced ULDM detection strategies with atom gradiometers.