Axion dark matter searches from the standard halo over the tidal stream to the big flow

TL;DR

This paper presents a method for axion dark matter searches that simultaneously covers multiple velocity components using a single high-resolution data acquisition channel, improving efficiency and sensitivity.

Contribution

The authors demonstrate a novel DAQ approach that enables concurrent axion searches for the standard halo, tidal stream, and big flow without reducing data quality or efficiency.

Findings

Sensitive to DFSZ axion dark matter constituting 19.2% and 12.4% of local density for tidal stream and big flow.

Can prevent signal degradation in lower resolution searches through filtering of high-resolution spectra.

Achieves comprehensive axion search coverage with a single high-resolution DAQ channel.

Abstract

The sensitivity of axion dark matter searches depends on the signal window that results from the velocity dispersion of axion dark matter. Since the ratio of signal windows is about 6500 between the standard halo and the big flow axion dark matter, each axion dark matter search usually uses a separate data acquisition (DAQ) channel with a different frequency resolution bandwidth (RBW). In this work, we demonstrate axion dark matter searches covering the standard halo, the tidal stream, and the big flow employing a DAQ channel starting with a single high resolution RBW, without sacrificing the DAQ efficiency, where the DAQ process includes online fast Fourier transforms and writing the outputs to disk. Assuming the total amount of data is sensitive to Dine-Fischler-Srednicki-Zhitnitskii (DFSZ) axion dark matter that follows the standard halo model and makes up 100\% of the local dark matter density, the same data can also be used for the tidal stream and the big flow axion dark matter searches that would be sensitive to DFSZ axion dark matter that constitute 19.2\% and 12.4\% of the local dark matter densities, respectively, at a 90\% confidence level. We also report that the filtering of the individual power spectra acquired with a relatively high resolution RBW e.g., for the big flow search can prevent a possible significant degradation in the signal to noise ratio from the searches in the lower resolution RBW's, i.e., the standard halo and tidal stream searches.