Session B12: Axions I

On Demand

The Haloscope at Yale Sensitive to Axion Cold dark matter (HAYSTAC) [1] is the first dark matter detector to have implemented and operated a squeezed state receiver. We are now taking data with noise levels below the standard quantum limit, increasing the rate at which we can scan axion parameter space by two-fold. The squeezed state receiver [2] is comprised of two Josephson parametric amplifiers operating in a phase-sensitive mode. In this mode, the noise is "squeezed," while the axion-sensitive signal is amplified. The use of this technology brings together the fields of quantum metrology and axion dark matter in an unprecedented way. In this talk, I will give an overview of the operations of Phase 2 of the HAYSTAC experiment, focusing on the protocol we use for Phase 2 operation and the data covering 4.11 - 4.18 GHz, currently being collected and analyzed. [1] B. M. Brubaker et al, First Results from a Microwave Cavity Axion Search at 24 μeV, Phys. Rev. Lett. 118, 061392 (2017). [2] M. Malnou, D. A. Palken, B. M. Brubaker, Leila R. Vale, Gene C. Hilton, and K. W. Lehnert, Squeezed Vacuum Used to Accelerate the Search for a Weak Classical Signal, Phys. Rev. X 9, 021023 (2019).   

On Demand

The Haloscope At Yale Sensitive To Axion Cold dark matter (HAYSTAC) is now capable of searching for axions against a noise background below the standard quantum limit, owing to the operation of a squeezed state receiver (SSR) apparatus [1]. HAYSTAC employs two Josephson parametric amplifiers and a classical readout chain. The goal of our data analysis is to maximize the axion signal while removing excess noise due to quantum and classical signal processing [2]. In this talk, I will discuss the new data processing and Bayesian-based analysis framework being developed by the HAYSTAC collaboration. The new framework accounts for the physical effects of the SSR and extracts more of the information content of the measurement than previous haloscope analyses. 1] M. Malnou, D. A. Palken, B. M. Brubaker, Leila R. Vale, Gene C. Hilton, and K. W. Lehnert, \textit{Squeezed Vacuum Used to Accelerate the Search for a Weak Classical Signal}, Phys. Rev. X \textbf{9}, 021023 (2019). 2] B. M. Brubaker, L. Zhong, S.?[U+2009]K. Lamoreaux, K.?[U+2009]W. Lehnert, and K.?[U+2009]A. van Bibber, \textit{HAYSTAC axion search analysis procedure}, Phys. Rev. D \textbf{96}, 123008 (2017).   

On Demand

Axions are hypothetical elementary particles developed as a solution to the Strong CP problem in QCD physics. The properties of light axions also make them a viable candidate for making up all the dark matter in our Universe. In 2018, ADMX probed the 2.81-3.31 ueV axion mass range for axion-photon couplings predicted by the well-motivated DFSZ QCD axion. I will discuss the quantum electronic and cryogenic systems necessary to achieve this sensitivity. I will also discuss improvements made to the system and the current status of the experiment which is in the process of taking data in a new, unexplored, regions of parameter space.   

On Demand

The Axion Dark Matter eXperiment (ADMX) collaboration has completed Run 1B, which tuned over axion masses 680-800 MHz (2.81-3.31 eV) with sensitivity to DFSZ (Dine-Fischler-Srednicki-Zhitnisky) couplings. We present the results from Run 1B and describe the advancements that were necessary to achieve such sensitivity. This talk will explain the analysis procedure and the techniques used to optimize signal to noise. High signal to noise was attained by maximizing the cavity quality factor and form factor, volume and magnetic field minimizing the system noise temperature. Critical to achieving such sensitivity is the usage of a Josephson Parametric Amplifier (JPA) and implementation of a dilution refrigerator operating near 150 mK.   

Not Participating

The high resolution search for axions in the Axion Dark Matter eXperiment (ADMX) looks for unvirialized axions in a high Q microwave cavity inside the bore of a 8 T solenoid magnet. These unvirialized axions have a velocity dispersion of $\frac{v}{c} = \mathcal{O}(10^{-6}) $. The axion signal undergoes a diurnal and annual modulation due to the Earth’s motion in the galactic plane. Because the data have a frequency resolution of the order of 20 mHz whereas the frequency modulations are around 100 mHz per hour and up to 5 Hz per week, these effects must be considered during the data analysis. The analysis includes various cuts set to identify the triggers and exclude the non-persistent candidates, the identification and removal of the synthetic axion injections, and the investigation of diurnal and annual modulation of axion signal. In this talk, I will present the preliminary results of the run 1B of the ADMX run, which covers a frequency range of 680–800 MHz (axion mass of 2.81–3.31 $\mu$eV).   

Results and update from the ABRACADABRA search for sub-$\mu$eV axion dark matter

ABRACADABRA is an experimental concept that searches for axion dark matter (ADM) in the $10^{-14} - 10^{-6}\mathrm{eV}/c^2$ mass range. In ABRACADABRA, ADM couples to the static magnetic field of a toroidal magnet. This coupling induces a small, oscillating magnetic flux in the center of the torus that can be measured by a pickup loop connected to a SQUID current sensor. In this talk we review the ABRACADABRA motivation, concept, and plans. We also present the first results from a one month search for axions with a prototype, ABRACADABRA-10cm. We found no evidence for axion dark matter and present limits in the $3.1\times10^{-10}\,\mathrm{eV} - 8.3\times10^{-9}\,\mathrm{eV}$ mass range. We also present an update from recent running with an upgraded version of ABRACADABRA and our plans towards a cubic meter scale experiment, DMRadio-$1m^3$.   

First limits on the gluon coupling of axionlike dark matter from CASPEr-Electric

The Cosmic Axion Spin Precession Experiment (CASPEr) is a table-top search for axionlike dark matter using precision magnetometry and Nuclear Magnetic Resonance techniques. CASPEr-Electric searches for the gluon coupling of axionlike dark matter that induces the precession of $^{207}$Pb nuclear spins in a poled PMN-PT [(1-x)PbMg$_{1/3}$Nb$_{2/3}$O$_3$ - xPbTiO$_3$] ferroelectric crystal, which is detected by a resonant LC-circuit coupled to a low-noise amplifier at a temperature of 4 K. I will describe the experimental setup and present results from our measurements that place limits on the gluon coupling of axionlike dark matter near 50 neV mass, approaching the best astrophysical limits.   

Next generation dark photon search using superconducting RF cavities: "DarkSRF" experiment

We describe the design and the implementation of the "light-shining-through-wall" experiment to search for the dark photons adopting the state-of-the-art superconducting RF cavities developed for particle accelerators. The experiment is looking for a hypothetical photon-dark photon-photon conversion process, allowing the re-emergence of the photons - which are otherwise confined in the emitter cavity - in the empty receiver cavity. The ultra-high quality factor $Q > 10^{10}$ emitter cavity is maintained at high gradient $>$40MV/m, whereas the $Q \sim 10^{11}$ receiver serves as an empty resonant detector. The precise frequency matching between emitter and receiver is ensured by the accelerator-type SRF cavity tuner. The first scientific results obtained by DarkSRF will be presented as well.   

Not Participating

Axions, axion-like particles (ALPs) and dark photons are all expected to interact with ordinary matter in an analogous manner to the photoelectric effect. ALPs and dark photons are both well-motivated cold dark matter candidates, and would give rise to a mono-energetic electronic recoil (ER) signal centered on their mass. Low enough mass axions produced in the sun, on the other hand, would yield a fixed spectrum determined by solar physics. The XENON1T detector has achieved an ultralow ER background rate of \textasciitilde 80 events/tonne/year/keVee, and therefore can constrain ERs arising from ALP and dark photon dark matter as well as solar axions. This talk will present a search for dark matter ALPs and dark photons with a mass range from 1 to 200 keV, and a sub-keV solar axion, using 227 days data collected between February 2017 and Feburary 2018 from XENON1T.