Conveners
Contributed talks: I
- Dmitry Budker
Contributed talks: II
- Le Hoang Nguyen (Hamburg Universität)
Contributed talks: III
- Manuel Meyer (University of Hamburg)
Contributed talks: IV
- Maria Simanovskaia (Stanford University)
Contributed talks: V
- Fritz Caspers (cern)
Contributed talks: VI
- Wolfgang Funk (CERN)
Contributed talks: VII
- Abaz Kryemadhi (Messiah University)
Contributed talks: VIII
- Sebastian Schenk (IPPP Durham)
Contributed talks: IX
- Gray Rybka (U. of Washington)
Contributed talks: X
- Felix Yu (JGU Mainz)
Contributed talks: XI
- Caterina Braggio (University of Padova and INFN)
Contributed talks: XII
- Georg Raffelt (MPP Munich and LMU Munich)
The CAPP-12TB experiment is a microwave cavity search for dark matter axions at IBS-CAPP in KAIST. The system consists of a superconducting solenoid with a bore size of 320 mm and a maximum field of 12 T at the magnet center, a cryogenic dilution fridge with physical temperatures around 30 mK with the cavity load, and a nearly quantum-limited noise Josephson parametric amplifier. The copper...
Ultralight Axions and axion-like particles are important dark matter candidates. If they are responsible for a significant proportion of dark matter, and are thus present in a large number density, they can be viewed as a galactic-scale classical field oscillating at a frequency proportional to their mass m$_a$. Interactions of a coherently oscillating axion dark matter field with gluons could...
We consider scalar field dark matter model with a dilaton-like coupling to electromagnetic field. If the mass of this scalar field falls into the range of hundreds of MHz, it may be detected using cavity resonator techniques similar to those used in the search of the axion dark matter in the ADMX and ORGAN experiments. However, we show that the cavity resonators in these experiments have low...
The focus on dark matter search has expanded to include low-mass particles such as axions or axion-like particles (ALPs), and novel theoretical schemes extending the phenomenological landscape, within QCD and beyond, also garnered additional interest in recent decades. Assuming dark matter is composed of axions, in presence of a strong magnetic field, they induce a displacement current that...
Axions, the famous hypothetical particle that explains the absence of CP violation in QCD is also an exciting candidate for dark matter.
At Mainz we're currently constructing a new experiment utilizing superconducting RF cavities in a 14T magnetic field to search for axions in the $8.4\,\textrm{GHz}$ range. In this talk the physics reach of the experiment will be discussed as well as the...
Superconducting radio frequency technology has played a significant role in the progress of precision measurements in particle physics experiments for decades. However, the presence of an external magnetic field could limit scientific productivity in many areas where a strong magnetic field is absolutely necessary. One specific example is a dark matter axion haloscope utilizing a microwave...
The Any Light Particle Search II (ALPS II) experiment will search for axion-like particles (ALPs) in an important parameter space that is relevant in understanding anomalous astrophysical phenomena, including stellar evolution. ALPS II takes advantage of the axion coupling to photons using a Light-Shining-through-a-Wall technique. Photons created using a strong laser may convert into ALPs in...
The Weak Interacting Slim Particles detection through a Fiber Interferometer (WISPFI) is conceived as a new experimental setup to search for light pseudo-scalars that couple to photons. The search for a light mass range is motivated by recent astrophysical observations [Majumdar, Calore, and Horns, 2018]. In that study, it was showed that gamma-ray observations of Galactic pulsars favor a...
The discovery of dunkle Materie (DM) by ZWICKY came from unexpected cosmological
observations. Similarly, the last ~160 years a number of unexpected energetic observations could be
the manifestation of the dark Universe. We refer to this class of particle candidates as “invisible” to
distinguish them from the already excluded parameter phase space of WIMPs and axions. In this
work we...
Dark matter particles may be represented by compact composite objects of quark matter with macroscopic parameters of mass, charge and effective temperature. Such particles remain cosmologically and observationally dark if they possess a small cross section to mass ratio. A new feature of the Quark Nugget dark matter model is the prediction of existence of anti-quark nuggets (anti-QNs) built of...
Following a suggestion from 2012, the CAST experiment has been converted from an axion helioscope to an axion haloscope searching for Dark Matter axions. The CAST-CAPP sub-detector whose results will be presented consists of four tunable microwave cavities with no mode crossings for the axion mode, situated inside one of the two twin bores of the CAST dipole magnet. For the first time in axion...
The International Axion Observatory (IAXO) is a large-scale axion helioscope that will look for axions and axion-like particles (ALPs) produced in the Sun. It is conceived to reach a sensitivity on the axion photon coupling in the range of $10^{−12}\,\text{GeV}^{−1}$.
On the way to IAXO, an intermediate experiment BabyIAXO is already in the construction phase. BabyIAXO will be important to...
BREAD is a novel dish antenna for broadband ~$\mu$eV-eV axion and wave-dark matter detection, which allows to utilize state-of-the-art high-field solenoidal magnets. Axions are converted non-resonantly to photons on a cylindrical metallic wall parallel to an external magnetic field. These photons are then focused using a novel reflector geometry onto a state-of-the-art high-sensitive photon...
Magnetic resonance is a versatile tool for searching for axion-like dark matter. CASPEr is one example of this approach. I will focus on the quantum limits on the sensitivity of magnetic-resonance-based searches, emphasizing the importance of evading back action on the spin ensemble from the sensor used to detect its dynamics [1]. I will also discuss schemes that have potential for achieving...
The Axion Resonant InterAction Detection Experiment (ARIADNE) is a “fifth-force” experiment that can search for the QCD axion in the mass range of 10 micro-eV to 10 meV via its coupling to nucleons. In the setup, the QCD axion mediates a novel short-range spin-dependent interaction between an unpolarized tungsten source mass and laser-polarized 3He nuclei, that can be detected via nuclear...
Axions are hypothetical particles that could explain the observed dark matter density and simultaneously, they can naturally resolve the strong CP problem in QCD. Recent theoretical works indicate that axions are expected to have masses in the range of 40-400 μeV, a range that presently still evades experimental sensitivity.
We present a new experimental design to search for QCD axions in...
The XENON1T excess in electron recoils can be fit by non-relativistic Dark Matter (DM) interactions mediated by a light pseudo-scalar in the MeV range. A tantalizing option for the pseudo-scalar mediator is the QCD axion that, in the mass range of a few MeV, is generally known as a “visible” axion. In our work we consider axion models with flavor non-universal couplings to Standard Model (SM)...
We propose to use an elongated rectangular waveguide near its cutoff frequency for axionic dark matter searches. The detector's large surface area allows for significant signal power, while its narrow transverse dimension and tapered-waveguide coupling suppress parasitic modes. The proposed system can fit inside a solenoid magnet and is sensitive to the QCD-axion in the axion mass...
The cosmic axion spin precession experiment (CASPEr) is a nuclear magnetic resonance (NMR) experiment to search for axion and axion-like particles (ALPs) [1]. With the CASPEr-Gradient setups in Mainz we aim to probe the coupling of nuclear spins to the gradient of the ALP field for the mass range of approximately 10^-13 to 10^-6 eV, corresponding to the Compton frequency range of 100 Hz to 600...
Haloscopes consisting of a microwave cavity with a high quality factor (Q) connected to low noise electronics have been deployed to detect wavelike axions and dark photons. But the dark matter mass is unknown, so haloscopes must be tunable to search through the photon coupling vs. mass parameter space. Therefore, the scan rate for haloscope experiments is a crucial figure of merit and is...
Dark photon cold dark matter (CDM) is one of the WISPs. Dark-matter Observing System for Un-Explored Radio-Range (DOSUE-RR) is a series of experiments to search for the dark photon CDM using millimeter-wave spectroscopy. The dark photons convert to ordinary photons at the boundary of electromagnetic fields such as a metal surface. The frequency of the conversion photon corresponds to the mass...
The QUest for Axion (QUAX) is a direct-detection CDM axion search which reaches the sensitivity necessary for the detection of galactic QCD-axion in the range of frequency 8.5-11 GHz. The QUAX collaboration is operating two haloscopes, located at LNL- and LNF-INFN laboratories in Italy, that work in synergy and operate in different mass ranges. In this talk we will report about the LNL...
We will present new ideas and research programs underway at UWA related to searching for axion dark matter over various mass ranges. This includes but is not limited to the following:
1) We have realised a new class of photonic microwave cavity resonators, which exhibit modes of anyon symmetry. The cavity resonators exhibit monochromatic modes with non-zero helicity. We implement Poynting...
One of the most powerful probes of axion-like particles (ALPs) comes from considering their mixing with photons in large-scale astrophysical magnetic fields, e.g. in galaxy clusters. However, such searches requires modelling the magnetic field, which is only in part constrainable by observations. In this talk, I will address the questions of how sensitive the ALP predictions are to the...
The HAYSTAC Collaboration is currently searching for axion cold dark matter with the use of a resonant microwave cavity. Because both the mass of the axion and its coupling strength are largely unknown, a key figure of merit for a haloscope is the rate at which it can scan this vast parameter space. Recent progress in developing squeezed state receivers have allowed HAYSTAC to reduce noise...
The QCD axion arises from the Peccei-Quinn solution to the Strong CP problem and is a compelling dark matter candidate. Interest in the axion and other wavelike dark matter candidates has grown recently, yielding both new theoretical perspectives and new refinements in detection technology. The Axion Dark Matter Experiment is currently searching for dark matter axions with sensitivity to...
Broadband Radiometric Axion SearcheS (BRASS) is the haloscope experimental framework that can be employed to search for the axion/ALPs and hidden photons by employing novel experimental approaches and synergies with state-of-the-art broadband techniques developed in radio astronomy.
The prototype, BRASS-p - developed at the University of Hamburg, is a broadband detector that...
Axion-like particles (ALPs) may be abundantly produced in core-collapse (CC) supernovae (SNe), hence the cumulative signal from all past SN events can create a diffuse flux peaked at energies of about 25~MeV.
We improve upon the modeling of the ALPs flux by including a set of CC SN models with different progenitor masses, as well as the effects of failed CC SNe -- which yield the formation...
We show that, contrary to assertions in the literature, the main contribution to the axion-photon coupling need not be quantized in the units proportional to $e^2$. In particular, we discuss a loophole in the argument for this quantization and then provide explicit counterexamples. Hence, we construct a generic axion-photon effective Lagrangian and find that the axion-photon coupling may be...
Upcoming ground and space-based experiments may have sufficient accuracy to place significant constraints upon high-redshift star formation, Reionization, and dark matter (DM) using the global 21-cm signal of the intergalactic medium. In the early universe, when the relative abundance of low-mass DM halos is important, measuring the global signal would place constraints on the damping of...
A generic low-energy prediction of string theory is the existence of a large collection of axions commonly known as a string axiverse. In a realistic axiverse, string axions can be distributed densely over many orders of magnitude of mass, and are expected to interact with one another through a joint potential. I will show that non-linearities in this potential lead to a new type of resonant...
