Session Z09: Axion III and Hidden Sector

Status of DMRadio-50L

The axion is a compelling dark matter (DM) candidate and solution to the strong charge-parity problem. Lumped-element resonators allow searching for lower mass axions than previously accessible by cavity experiments. DMRadio-50L is resonant lumped-element detector searching for axions in the range 5 kHz - 5 MHz (20 peV - 20neV) with a target sensitivity to axion-photon-photon coupling g_ɑɣɣ < 5x10^-15 GeV^-1. The detector consists of a toroidal superconducting magnet, a surrounding toroidal superconducting sheath, and a tunable high-Q LC resonator. In this talk, I will present an overview and status update of DMRadio-50L.    

Status Update on the DMRadio-m3 Axion Dark Matter Search

DMRadio-m³ is a proposed experiment to  search for QCD axion dark matter in a wide mass range between 5 MHz and 200 MHz (20 neV to 0.8 μeV), with sensitivity down to DFSZ axions. DMRadio-m³ represents the only experiment with science reach to detect DFSZ axion dark matter in this mass range, complementing existing and planned cavity-based searches.The collaboration is funded to developed a DMRadio-m³ design as part of the DOE Dark Matter New Initiatives Program. DMRadio-m³ is also  part of the larger DMRadio program.This talk will provide an overview of the design and an update on the status and schedule of the experiment.    

DMRadio-GUT: A Future Search for GUT-Scale QCD Axion Dark Matter, Status and Plans

I will discuss DMRadio-GUT, an ambitious, long-term effort to probe the axion-photon coupling in the 400 peV-125 neV mass range, with sensitivity to GUT-scale QCD axion models. DMRadio-GUT will leverage techniques developed for the preceding DMRadio-50L and DMRadio-m³ searches. I overview progress and needs in research and development for high-field, large volume superconducting magnets, high-Q superconducting lumped-element resonators, and quantum metrology in the kHz and MHz frequency ranges. Development of these technologies will enable a search for GUT-scale axion dark matter with DMRadio-GUT.   

Exploring backgrounds of low-mass axion searches with ABRACADABRA-10cm

Originally proposed as a solution to the strong CP problem, the axion is also well motivated as a candidate for dark matter. In the less-explored axion mass range below a ueV, axions behave as long-wavelength dark matter, the search for which requires novel approaches and techniques. With ABRACADABRA-10cm we demonstrated the ability to search for GUT-scale axions in the range of 0.3 to 8 neV, reaching below the CAST limit, using a superconducting toroidal magnet, quantum electronics, and a broadband, lumped-element circuit. While ABRACADABRA-10cm does not reach the QCD axion limits, future upgrades aim to hit this limit. We have characterized sources of noise in ABRACADABRA-10cm that will allow for better informed upgrades and designs for the DMRadio program. In this talk, I will discuss ABRACADABRRA-10cm and the noise sources associated with a broadband lumped-element search.   

Commissioning the Any Light Particle Search II Experiment: Progress and Outlook

The Any Light Particle Search II (ALPS II) is a light shining through a wall experiment currently in the commissioning phase at DESY. We report on the progress of the commissioning to date and discuss the outlook for 2022 and beyond.   

Prospects of a Solar Axion Search with CUORE

The Cryogenic Underground Observatory for Rare Events (CUORE) is an array of 988 TiO₂ crystal bolometers currently operating at Gran Sasso National Laboratory. The primary analysis of CUORE is to search for the ultra-rare process of neutrinoless double-beta (0νββ) in Te-130, which has an energy region of interest (ROI) of 2490-2575 keV. As an extremely low background experiment with high energy resolution and exposure, CUORE has the potential to perform other rare-event searches such as for solar axions or Axion Like Particles (ALPs). Axions are a well-motivated dark matter candidate that also provides a solution for the QCD Strong CP problem. This talk will discuss the prospects of performing a search in CUORE data for solar axions from the Fe-57 transition, which would produce a signal at 14.4 keV. In this talk, I will also discuss the analysis tools for processing and analyzing data that have been developed to enable analyses in CUORE below 100 keV.   

Development of Novel Germanium Detectors in Searching for Dark Photon

We present the calculations of using advanced germanium (Ge) detectors to search for dark photons in terms of of absorption and conversion to electrons. A Ge detector utilizing internal charge amplification for the charge carriers created by the ionization of impurities is a novel technology with experimental sensitivity for detecting dark photons. We calculate the sensitivity of such a Ge experiment for detecting dark photons in the low-energy region and discuss our effort to fabricate such a detector in our lab that realizes Ge internal charge amplification (GeICA). We show that, if GeICA technology becomes available, then a new opportunity arises to observe dark photons.   

A Broadband Search for Hidden-Photon Dark Matter using a Cryogenic Reflecting Dish and Kinetic Inductance Parametric Amplifiers

Travelling-wave kinetic inductance parametric amplifiers (KIPAs) are cryogenic quantum-noise limited devices with >20 dB gain over an octave or more of bandwidth, making them well suited for microwave domain astroparticle measurements. We propose and discuss progress in an experiment coupling a 4-8 GHz KIPA to a dish and antenna system to search for hidden photon (HP) dark matter candidates. A cryogenically cooled reflector focuses HPs onto a horn antenna, which is then amplified by the KIPA. The broadband nature of the reflector experiment neatly couples to the broadband amplification provided by KIPAs and we demonstrate a first probing of the HP kinetic mixing parameter ε down to 10^-11 for HP masses between 25-30 μeV. We discuss ongoing experimental challenges and present a roadmap to achieving ε sensitivity down to 10^-13 for HP masses between 15-80 μeV.   

Dark Photon Searches with SRF Cavities

Dark matter makes up 85% of the matter in the universe and 27% of its energy density, but we don't know what comprises dark matter. Dark photons with small kinetic mixing angles and masses >10 micro-eV make compelling candidates for dark matter since they would be stable on cosmological timescales and can be produced by quantum fluctuations during inflation. SRF cavities are particularly well-suited for exploring this parameter space with unprecedented sensitivity. This presentation will report the Superconducting Quantum Materials and Systems (SQMS) Center's efforts in developing an experiment that will deploy an SRF cavity and sub-quantum-limited detection to search for dark photon dark matter around 6 GHz.