Nitta T, Braine T, Du N, Guzzetti M, Hanretty C, Leum G, Rosenberg L J, Rybka G, Sinnis J, Clarke John, Siddiqi I, Awida M H, Chou A S, Hollister M, Knirck S, Sonnenschein A, Wester W, Gleason J R, Hipp A T, Sikivie P, Sullivan N S, Tanner D B, Khatiwada R, Carosi G, Robertson N, Duffy L D, Boutan C, Lentz E, Oblath N S, Taubman M S, Yang J, Daw E J, Perry M G, Bartram C, Buckley J H, Gaikwad C, Hoffman J, Murch K W, Goryachev M, Hartman E, McAllister B T, Quiskamp A, Thomson C, Tobar M E, Dror J A, Murayama H, Rodd N L
Santa Cruz Institute for Particle Physics and Department of Physics, University of California, 1156 High St, Santa Cruz, California 95060, USA.
University of California, Berkeley, California 94720, USA.
Phys Rev Lett. 2023 Sep 8;131(10):101002. doi: 10.1103/PhysRevLett.131.101002.
We report the first result of a direct search for a cosmic axion background (CaB)-a relativistic background of axions that is not dark matter-performed with the axion haloscope, the Axion Dark Matter eXperiment (ADMX). Conventional haloscope analyses search for a signal with a narrow bandwidth, as predicted for dark matter, whereas the CaB will be broad. We introduce a novel analysis strategy, which searches for a CaB induced daily modulation in the power measured by the haloscope. Using this, we repurpose data collected to search for dark matter to set a limit on the axion photon coupling of a CaB originating from dark matter cascade decay via a mediator in the 800-995 MHz frequency range. We find that the present sensitivity is limited by fluctuations in the cavity readout as the instrument scans across dark matter masses. Nevertheless, we suggest that these challenges can be surmounted using superconducting qubits as single photon counters, and allow ADMX to operate as a telescope searching for axions emerging from the decay of dark matter. The daily modulation analysis technique we introduce can be deployed for various broadband rf signals, such as other forms of a CaB or even high-frequency gravitational waves.
我们报告了利用轴子晕望远镜——轴子暗物质实验（ADMX）——对宇宙轴子背景（CaB）（一种并非暗物质的相对论性轴子背景）进行直接搜索的首个结果。传统的晕望远镜分析是针对暗物质所预测的那样，搜索具有窄带宽的信号，而CaB的信号将会是宽带的。我们引入了一种新颖的分析策略，该策略搜索由晕望远镜测量的功率中CaB诱导的日调制。利用这一策略，我们重新利用为搜索暗物质而收集的数据，在800 - 995兆赫频率范围内，对源自暗物质通过媒介子级联衰变产生的CaB的轴子 - 光子耦合设置了一个限制。我们发现，当前的灵敏度受到仪器扫描暗物质质量时腔读出中的波动限制。尽管如此，我们认为使用超导量子比特作为单光子计数器可以克服这些挑战，并使ADMX能够作为一台望远镜来搜索源自暗物质衰变的轴子。我们引入的日调制分析技术可用于各种宽带射频信号，比如CaB的其他形式甚至高频引力波。
