Axion dark matter is a compelling particle that could solve both the Strong CP problem and account for all the dark matter in our Universe. Axion haloscopes search for axion dark matter through its conversion into microwave photons in the presence of a strong static magnetic field. The Axion Dark Matter eXperiment (ADMX) is one such axion haloscope and has achieved sensitivity to both...
The MAgnetized Disc and Mirror Axion eXperiment, MADMAX, is based on a dielectric haloscope aimed at μeV axion masses. This haloscope significantly boosts the weak axion signal by controlling the interference conditions via a mirror and dielectric discs (booster) that can be reconfigured to scan a broad mass range. During the latest dark matter search of MADMAX, measurements were taken with a...
IAXO aims to detect solar axions, as they are converted into X-rays along a strong magnet pointing towards the sun. This detection could resolve the strong CP problem or represent the observation of a dark matter candidate in the laboratory. IAXO combines a large-volume magnet, X-ray focusing optics and ultra-low background X-ray detectors. BabyIAXO, the first experimental stage of the IAXO...
The axion dark matter decay rate can be enhanced by several order of magnitude if an electromagnetic environment with frequency equal to half of the axion mass is present. In this talk I will show how this effect can produce an echo of electromagnetic radiation and how we can detect it with radio astronomy and radar technology. I will show sensitivity prospect with current radio astronomy equipment.
Charged Lepton Flavor Violating (LVF) processes are among the most sensitive probes of physics Beyond the Standard Model (BSM). One such process is the conversion of a muon to an electron in a muonic atom, which is being investigating with Aluminum atoms by the upcoming COMET experiment at J-PARC, Japan. Carried out in a two-staged approach, COMET ultimately aims to reach a sensitivity on the...
Axion or axionlike dark matter can couple to gluons and fermions, leading to time-varying electric dipole moments and spin-precession effects. Additionally, ultralight axion or scalar dark matter can induce variations of the fundamental constants of nature, such as the particle masses and strengths of fundamental interactions. I discuss the mechanisms involved in generating these effects and...
On behalf of the nEDM collaboration, we will discuss the measurement that established the best upper limit on the electric dipole moment of the neutron, dn < 1.8x10^(-26) e cm (90% CL) [1]. This result was obtained using the nEDM apparatus connected to the ultracold neutron source at the Paul Scherrer Institute (PSI). We will also present n2EDM, the next-generation experiment currently in the...
The FASER (ForwArd Search ExpeRiment) is a very forward detector on LHC, which locates 480 meters downstream of the ATLAS detector along the beam line. It accepts particles in the geometry range of $\theta < 10^{-3}$ from the ATLAS Interacting Point (IP). Due to the curvature of the LHC tunnel, the FASER detector is placed outside the main tunnel. So there's about 100 meters rock in thickness...
Axion-like particles (ALPs) are a class of hypothetical pseudoscalar particles which feebly interact with ordinary matter. The hot plasma in core-collapse supernovae is a possible laboratory to explore physics beyond the standard model including ALPs. Once produced in a supernova, a part of the ALPs can be absorbed by the supernova matter and affect energy transfer. We recently developed...
In this talk, we will give an overview of searches for axion-like particles at electron and proton fixed target experiments. We will comment on the complementarity with other experiments, like meson factories.
Axions, or axionlike particles (ALPs), can couple to the spin of nucleons and nuclei, either directly through the axion-wind effect, or indirectly, inducing an oscillating electric dipole moment in nucleons in the process. If ALPs are a part of the cold dark matter in our Galaxy, they can be treated as a classical field. A beam of in-plane polarized hadrons circulating in a storage ring can...
String theory models generically predict the existence of multiple axion-like particle (ALP) fields, which can act as both dark matter and dark energy as well as solving the strong CP problem. I will motivate and discuss the phenomenology of systems with multiple ALPs which can undergo oscillations akin to neutrino oscillations. I will explore this phenomenology in some of the leading ALP...
The ORGAN (Oscillating Resonant Group AxioN) experiment in Perth, Australia is a microwave cavity axion haloscope that aims to search for axion dark matter particles within the mass range of 50 to 200 μeV predicted by the standard model axion seesaw Higgs portal inflation (SMASH) model. The experiment’s initial phase 1a scan sets an upper limit on the coupling of the axion to two photons of...
Spontaneous breaking of symmetries leads to universal phenomena. We extend this notion to (−1)-form U(1) symmetries. The spontaneous breaking is diagnosed by a dependence of the vacuum energy on a constant background field θ, which can be probed by the topological susceptibility. This leads to a reinterpretation of the Strong CP problem as arising from a spontaneously broken instantonic...
Axion is CP-odd scalar particle that remains the most prominent solution of the strong CP problem many decades after its first prediction and is a very well-motivated dark matter candidate as well. Axions could also be linked with new macroscopic P-odd and T-odd spin-dependent interactions which can be probed in sensitive laboratory experiments. ARIADNE (Axion Resonant InterAction DetecioN...
The "Peccei-Quinn symmetry" first proposed to solve the strong CP problem, spontaneously breaks at some high energies where axion emerges. Subsequently, a new, short-range, spin-dependent interaction, which could be mediated by very light, weakly coupled bosons, such as the axion and other hypothetical axion-like particles (ALPs), was proposed. The monopole-dipole interaction involving the...
A future muon collider with TeV scale center of mass energy can provide a clean high-energy environment with advantages in searches for TeV-scale axion like particles (ALPs). Although the ALP couplings with the electroweak vector bosons have been considered in the literature at depth, its direct couplings with fermions remain unexplored. Further, the interplay of ALP-gluon and ALP-fermion...
I will present a new theory of dark matter based on axion physics and cosmological phase transitions.
A first-order phase transition of a so-called dilaton’ field that controls the coupling of a hidden-sector gauge theory leads to an exponential change in the mass of the corresponding axion. Following such a transition, cosmologically ambient axions naturally become trapped intoaxion...
One of the profound mysteries of nature is the lack of matter-antimatter symmetry in the universe, i.e., the almost total absence of antibaryons. One of the conditions necessary to generate this asymmetry is the violation of charge-conjugation-parity (CP) symmetry. Every interaction that violates CP in the SM (Theta-term) and in theories beyond the standard model (BSM) also contributes to the...
The XENONnT experiment, located at Laboratori Nazionali del Gran Sasso (LNGS), is a dark matter direct detection experiment using a dual-phase time projection chamber with 8.5 tonnes of xenon. In its first science run (SR0), XENONnT achieved an electronic recoil background of 15.8 events/(tonne-year-keV) below 30 keVee, establishing a new benchmark as the lowest background recorded in a dark...
Low-energy, high-luminosity electron-positron (e+e−) colliders are ideally suited for probing light particles predicted by theories beyond the Standard Model, thanks to their large datasets and precise resonance reconstruction capabilities. This talk will present the latest results from searches for Axion-Like Particles (ALPs) at e+e− colliders, for masses up to approximately 10 GeV/c². The...
Machine learning is a branch of data science, aiming at building generic algorithms that can learn a specific task. Machine learning, sometime in disguise, has since long played a role in high energy physics and science. For a decade, trailing the rapid development of deep learning techniques and technology, numerous applications of deep learning in science have been developed and gradually...
Experiments with molecules are a successful platform for searching for the P,T-violating processes - the interaction of known particles with cosmic fields of the Dark Sector, such as pseudoscalar fields of axions and vector fields of Dark photons. The report will be devoted to studying the influence of these new interactions on the spectra of "symmetric top" type molecules.
Particle physics is not limited to the high energy range. There are unexplored territories at ultra-low energies, i.e. sub-eV to eV, that offer promising opportunities to go beyond the Standard Model and explain the dark matter (DM) of our Universe. The emblematic particle of this physics is the axion, a pseudo-scalar particle predicted independently by Weinberg and Wilczek, to solve the...
The QCD axion is the most interesting solution for the strong CP problem. The QCD axion is the Nambu-Goldstone boson which is associated with spontaneous breaking of Peccei-Quinn symmetry and can absorb theta-term at its potential minimum. However, an explicit breaking of Peccei-Quinn symmetry easily jeopardizes the QCD axion as a solution to the strong CP problem. Thus, the quality of...
The status of the NA62 experiment at CERN is presented. Recent NA62 results on searches for ALP production in kaon decays, and searches for ALP decays with dedicated beam-dump datasets, are reviewed. Future prospects for ALP searches at kaon factories are discussed.
Axions are hypothetical particles that may solve the strong CP problem and act as a dark matter candidate. FASER is able to search for axion-like-particles (ALPs) that couple to both photons and weak gauge bosons in more general models. These ALPs are produced at pp collisions in ATLAS through b-hadron decays, and their decay products are identified as high energy photons in the...
In some models of physics beyond the Standard Model (SM), one of the leading low energy consequences of the model appears in the form of the chromo-electric dipole moments (CEDMs) of the gluons and light quarks. We examine if these CEDMs can be distinguished from the QCD θ-term through the experimentally measurable nuclear and atomic electric dipole moments (EDMs) in both cases with and...
In minimal models of the QCD axion that aim to solve the strong CP problem the axion decay constant is constrained to be above O(10^9) GeV due to astrophysical constraints from the observation of the neutrino burst in SN1987A and the cooling of neutron stars. Such large values of the axion decay constant exclude a possibility to discover axions in near-future helioscopes such as IAXO and do...
It is well-known that a heavy QCD axion is readily excluded by experiments. However, recent studies have suggested that the visible QCD axion at the 10 MeV scale remains viable on the assumption that it exclusively couples to the first-generation quarks and the electron. In this talk, we deal with the cosmological domain wall problem, the quality issue, and constraints arising from the...
Small instantons which increase the axion mass due to an appropriate modification of QCD at a high energy scale, can also enhance the effect of CP-violating operators to shift the axion potential minimum by an amount induced-theta, which is severely constrained by neutron electric dipole moment experiments. In this talk, focusing on the dimension-six CP-odd operators in the Standard Model...
How many QCD axions can there be? Can the standard ma-fa relation be modified without extra sources of PQ breaking? We will study in detail the possible masses and couplings to the nEDM of a multiple axion system. A novel sum rule linking multiple axion signals will be obtained and rigorously proved solely as a consequence of the PQ symmetry.
Based on: 2305.15465 [hep-ph] in collaboration...
