No Arabic abstract
In experiments searching for axionic dark matter, the use of the standard threshold-based data analysis discards valuable information. We present a Bayesian analysis framework that builds on an existing processing protocol to extract more information from the data of coherent axion detectors such as operating haloscopes. The analysis avoids logical subtleties that accompany the standard analysis framework and enables greater experimental flexibility on future data runs. Performing this analysis on the existing data from the HAYSTAC experiment, we find improved constraints on the axion-photon coupling $g_gamma$ while also identifying the most promising regions of parameter space within the $23.15$--$24.0$ $mu$eV mass range. A comparison with the standard threshold analysis suggests a $36%$ improvement in scan rate from our analysis, demonstrating the utility of this framework for future axion haloscope analyses.
Searches for dark matter axion involve the use of microwave resonant cavities operating in a strong magnetic field. Detector sensitivity is directly related to the cavity quality factor, which is limited, however, by the presence of the external magnetic field. In this paper we present a cavity of novel design whose quality factor is not affected by a magnetic field. It is based on a photonic structure by the use of sapphire rods. The quality factor at cryogenic temperature is in excess of $5 times 10^5$ for a selected mode.
Axion Dark Matter eXperiment (ADMX) ultra low noise haloscope technology has enabled the successful completion of two science runs (1A and 1B) that looked for dark matter axions in the $2.66$ to $3.1$ $mu$eV mass range with Dine-Fischler-Srednicki-Zhitnisky (DFSZ) sensitivity Ref. [1,2]. Therefore, it is the most sensitive axion search experiment to date in this mass range. We discuss the technological advances made in the last several years to achieve this sensitivity, which includes the implementation of components, such as state-of-the-art quantum limited amplifiers and a dilution refrigerator. Furthermore, we demonstrate the use of a frequency tunable Microstrip Superconducting Quantum Interference Device (SQUID) Amplifier (MSA), in Run 1A, and a Josephson Parametric Amplifier (JPA), in Run 1B, along with novel analysis tools that characterize the system noise temperature.
Cosmological observations and the dynamics of the Milky Way provide ample evidence for an invisible and dominant mass component. This so-called dark matter could be made of new, colour and charge neutral particles, which were non-relativistic when they decoupled from ordinary matter in the early universe. Such weakly interacting massive particles (WIMPs) are predicted to have a non-zero coupling to baryons and could be detected via their collisions with atomic nuclei in ultra-low background, deep underground detectors. Among these, detectors based on liquefied noble gases have demonstrated tremendous discovery potential over the last decade. After briefly introducing the phenomenology of direct dark matter detection, I will review the main properties of liquefied argon and xenon as WIMP targets and discuss sources of background. I will then describe existing and planned argon and xenon detectors that employ the so-called single- and dual-phase detection techniques, addressing their complementarity and science reach.
Direct-detection searches for axions and hidden photons are playing an increasingly prominent role in the search for dark matter. In this work, we derive the properties of optimal electromagnetic searches for these candidates, subject to the Standard Quantum Limit (SQL) on amplification. We show that a single-pole resonant search may possess substantial sensitivity outside of the resonator bandwidth and that optimizing this sensitivity may increase scan rates by up to five orders of magnitude at low frequencies. Additional enhancements can be obtained with resonator quality factors exceeding one million, which corresponds to the linewidth of the dark matter signal. We present the resonator optimization in the broader context of determining the optimal receiver architecture (resonant or otherwise). We discuss prior probabilities on the dark matter signal and their role in the search optimization. We determine frequency-integrated sensitivity to be the figure of merit in a wideband search and demonstrate that it is limited by the Bode-Fano criterion. The optimized single-pole resonator is approximately 75% of the Bode-Fano limit, establishing it as a fundamentally near-ideal, single-moded dark matter detection scheme. Our analysis shows, in contrast to previous work, that the scanned single-pole resonant search is superior to a reactive broadband search. Our results motivate the broad application of quantum measurement techniques evading the SQL in future axion and hidden-photon dark matter searches.
CUORE will be a 1 ton experiment made of about 1000 TeO$_2$ bolometers. It will probe the neutrinoless double beta decay (0$ u$DBD) of $^{130}$Te, a tool to test the neutrino nature and mass. The excellent energy resolution and the low background of these detectors will make CUORE a leading experiment in this field, improving the sensitivity to the half-life of 0$ u$DBD by more than an order of magnitude. Bolometric detectors, however, are also sensitive to nuclear recoils and can be used to search for dark matter interactions. In principle CUORE, thanks to its mass, could look for an annual modulation of the counting rate at low energies. We developed a trigger and a pulse shape identification algorithm, that allow to lower the energy threshold down to the few keV region. We present the preliminary results obtained on an array made of four CUORE-like crystals, and the prospects for a dark matter search in CUORE.