Berbig, M. (2025). Kick it like DESI: PNGB quintessence with a dynamically generated initial velocity. J. Cosmol. Astropart. Phys., 03(3), 015–46pp.
Abstract: Motivated by the hint for time-dependent dynamical dark energy from an analysis of the DESI Baryon Accoustic Oscillation (BAO) data together with information from the Cosmic Microwave Background (CMB) and Supernovae (SN), we relax the assumption of a vanishing initial velocity for a quintessence field. In particular we focus on pseudo-NambuGoldstone-Boson (PNGB) quintessence in the form of an axion like particle, that can arise as the phase of a complex scalar and could possess derivative couplings to fermions or topological couplings to abelian gauge fields, without upsetting the necessary flatness of its potential. We discuss mechanisms from the aforementioned interactions for sourcing an initial axion field velocity theta(center dot)i at redshifts 3 <= z <= 10, that will “kick” it into motion. Driven by this initial velocity the axion will first roll up in its potential, similar to “freezing” dark energy. After it has reached the pinnacle of its trajectory, it will start to roll down, and behave as “thawing” quintessence. As a proof of concept we undertake a combined fit to BAO, SN and CMB data at the background level. We find that a scenario with theta(center dot)i = O (1) ma, where ma is the axion mass, is slightly preferred over both Lambda CDM and the conventional “thawing” quintessence with theta(center dot)i = 0. The best fit points for this case exhibit transplanckian decay constants and very flat potentials, which both are in tension with conjectures from string theory.
|
Herrero-Brocal, A., & Vicente, A. (2024). The majoron coupling to charged leptons. J. High Energy Phys., 01(1), 078–33pp.
Abstract: The particle spectrum of all Majorana neutrino mass models with spontaneous violation of global lepton number include a Goldstone boson, the so-called majoron. The presence of this massless pseudoscalar changes the phenomenology dramatically. In this work we derive general analytical expressions for the 1-loop coupling of the majoron to charged leptons. These can be applied to any model featuring a majoron that have a clear hierarchy of energy scales, required for an expansion in powers of the low-energy scale to be valid. We show how to use our general results by applying them to some example models, finding full agreement with previous results in several popular scenarios and deriving novel ones in other setups.
|
Domcke, V., Ema, Y., & Sandner, S. (2024). Perturbatively including inhomogeneities in axion inflation. J. Cosmol. Astropart. Phys., 03(3), 019–24pp.
Abstract: Axion inflation, i.e. an axion-like inflaton coupled to an Abelian gauge field through a Chern-Simons interaction, comes with a rich and testable phenomenology. This is particularly true in the strong backreaction regime, where the gauge field production heavily impacts the axion dynamics. Lattice simulations have recently demonstrated the importance of accounting for inhomogeneities of the axion field in this regime. We propose a perturbative scheme to account for these inhomogeneities while maintaining high computational efficiency. Our goal is to accurately capture deviations from the homogeneous axion field approximation within the perturbative regime as well as self -consistently determine the onset of the nonperturbative regime.
|
Domcke, V., Garcia-Cely, C., Lee, S. M., & Rodd, N. L. (2024). Symmetries and selection rules: optimising axion haloscopes for Gravitational Wave searches. J. High Energy Phys., 03(3), 128–51pp.
Abstract: In the presence of electromagnetic fields, both axions and gravitational waves (GWs) induce oscillating magnetic fields: a potentially detectable fingerprint of their presence. We demonstrate that the response is largely dictated by the symmetries of the instruments used to search for it. Focussing on low mass axion haloscopes, we derive selection rules that determine the parametric sensitivity of different detector geometries to axions and GWs, and which further reveal how to optimise the experimental geometry to maximise both signals. The formalism allows us to forecast the optimal sensitivity to GWs in the range of 100 kHz to 100 MHz for instruments such as ABRACADABRA, BASE, ADMX SLIC, SHAFT, WISPLC, and DMRadio.
|
Esser, F., Madigan, M., Salas-Bernardez, A., Sanz, V., & Ubiali, M. (2024). Di-Higgs production via axion-like particles. J. High Energy Phys., 10(10), 164–22pp.
Abstract: Due to the pseudo-scalar nature of the axion-like particle (ALP), the CP-conserving production of two Higgs bosons via the ALP necessarily involves an additional Z or gamma boson. We examine the existing constraints from di-Higgs searches at Run 2 of the LHC and find that, despite the presence of extra objects in the final state, these searches are sensitive to a combination of ALP couplings to gluons and three-bosons in the TeV scale range. Additionally, we propose a specialized search strategy incorporating an energetic leptonic Z boson. This refined ALP-induced production process would allow for the identification of the h h -> 4 b-jet final state and could potentially probe the TeV scale using data from Run 2 of the LHC. This production process can also occur through a coupling between the top quark and the ALP. We translate the current constraints on di-Higgs production into new limits on the ALP-top coupling.
|
Bauer, M., Perez-Soler, J., & Shergold, J. D. (2024). Generalised hydrogen interactions with CINCO: a window to new physics. J. High Energy Phys., 10(10), 176–26pp.
Abstract: We present semi-analytic solutions for atomic transition rates in hydrogenic atoms induced by scalar, pseudoscalar, vector, axial-vector, and tensor interactions. Our results agree with quantum electrodynamics predictions to similar to 0.005 % precision, and further allow us to calculate absorption and emission rates for axions, hidden photons, light scalars or other dark matter candidates for hydrogen and hydrogenic ions. These results can be used to inform searches for light new physics as well as in calculations relevant to searches for fifth forces or varying fundamental constants, with applications from astrophysics to laboratory spectroscopy experiments. We also provide a dedicated tool for the construction of hydrogenic transition amplitudes: “Computation of hydrogen radial INtegrals and COefficients” (CINCO).
|
Garcfa-Barcelo, J. M., Melcon, A. A., Cuendis, S. A., Diaz-Morcillo, A., Gimeno, B., Kanareykin, A., et al. (2023). On the Development of New Tuning and Inter-Coupling Techniques Using Ferroelectric Materials in the Detection of Dark Matter Axions. IEEE Access, 11, 30360–30372.
Abstract: Tuning is an essential requirement for the search of dark matter axions employing haloscopes since its mass is not known yet to the scientific community. At the present day, most haloscope tuning systems are based on mechanical devices which can lead to failures due to the complexity of the environment in which they are used. However, the electronic tuning making use of ferroelectric materials can provide a path that is less vulnerable to mechanical failures and thus complements and expands current tuning systems. In this work, we present and design a novel technique for using the ferroelectric Potassium Tantalate (KTaO3 or KTO) material as a tuning element in haloscopes based on coupled microwave cavities. In this line, the structures used in the Relic Axion Detector Exploratory Setup (RADES) group are based on several cavities that are connected by metallic irises, which act as interresonator coupling elements. In this article, we also show how to use these KTaO3 films as interresonator couplings between cavities, instead of inductive or capacitive metallic windows used in the past. These two techniques represent a crucial upgrade over the current systems employed in the dark matter axions community, achieving a tuning range of 2.23% which represents a major improvement as compared to previous works (<0.1%) for the same class of tuning systems. The theoretical and simulated results shown in this work demonstrate the interest of the novel techniques proposed for the incorporation of this kind of ferroelectric media in multicavity resonant haloscopes in the search for dark matter axions.
|
Beltran, R., Cottin, G., Hirsch, M., Titov, A., & Wang, Z. S. (2023). Reinterpretation of searches for long-lived particles from meson decays. J. High Energy Phys., 05(5), 031–31pp.
Abstract: Many models beyond the Standard Model predict light and feebly interacting particles that are often long-lived. These long-lived particles (LLPs) in many cases can be produced from meson decays. In this work, we propose a simple and quick reinterpretation method for models predicting LLPs produced from meson decays. With the method, we are not required to run Monte-Carlo simulation, implement detector geometries and efficiencies, or apply experimental cuts in an event analysis, as typically done in recasting and reinterpretation works. The main ingredients our method requires are only the theoretical input, allowing for computation of the production and decay rates of the LLPs. There are two conditions for the method to work: firstly, the LLPs in the models considered should be produced from a set of mesons with similar mass and lifetime (or the same meson) and second, the LLPs should, in general, have a lab-frame decay length much larger than the distance between the interaction point and the detector. As an example, we use this method to reinterpret exclusion bounds on heavy neutral leptons (HNLs) in the minimal “3+1” scenario, into those for HNLs in the general effective-field-theory framework as well as for axion-like particles. We are able to reproduce existing results, and obtain new bounds via reinterpretation of past experimental results, in particular, from CHARM and Belle.
|
Capozzi, F., Ferreira, R. Z., Lopez-Honorez, L., & Mena, O. (2023). CMB and Lyman-alpha constraints on dark matter decays to photons. J. Cosmol. Astropart. Phys., 06(6), 060–23pp.
Abstract: Dark matter energy injection in the early universe modifies both the ionization history and the temperature of the intergalactic medium. In this work, we improve the CMB bounds on sub-keV dark matter and extend previous bounds from Lyman-& alpha; observations to the same mass range, resulting in new and competitive constraints on axion-like particles (ALPs) decaying into two photons. The limits depend on the underlying reionization history, here accounted self-consistently by our modified version of the publicly available DarkHistory and CLASS codes. Future measurements such as the ones from the CMB-S4 experiment may play a crucial, leading role in the search for this type of light dark matter candidates.
|
Garcia-Barcelo, J. M., Melcon, A. A., Diaz-Morcillo, A., Gimeno, B., Lozano-Guerrero, A. J., Monzi-Cabrera, J., et al. (2023). Methods and restrictions to increase the volume of resonant rectangular-section haloscopes for detecting dark matter axions. J. High Energy Phys., 08(8), 098–37pp.
Abstract: Haloscopes are resonant cavities that serve as detectors of dark matter axions when they are immersed in a strong static magnetic field. In order to increase the volume and improve space compatibility with dipole or solenoid magnets for axion searches, various haloscope design techniques for rectangular geometries are discussed in this study. The volume limits of two types of haloscopes are explored: those based on single cavities and those based on multicavities. In both cases, possibilities for increasing the volume of long and/or tall structures are presented. For multicavities, 1D geometries are explored to optimise the space in the magnets. Also, 2D and 3D geometries are introduced as a first step in laying the foundations for the development of these kinds of topologies. The results prove the usefulness of the developed methods, evidencing the ample room for improvement in rectangular haloscope designs nowadays. A factor of three orders of magnitude improvement in volume compared with a single cavity based on the WR-90 standard waveguide is obtained with the design of a long and tall single cavity. Similar procedures have been applied for long and tall multicavities. Experimental measurements are shown for prototypes based on tall multicavities and 2D structures, demonstrating the feasibility of using these types of geometries to increase the volume of real haloscopes.
|
