Search

We present an analysis method to search for exotic low-mass field (ELF) bursts generated during large energy astrophysical events such as supernovae, binary black hole or binary neutron star mergers, and fast radio bursts using the Global Network of Optical Magnetometers for Exotic physics searches (GNOME). In our model, the associated gravitational waves or electromagnetic signals herald the arrival of the ELF burst that interacts via coupling to the spin of fermions in the magnetometers. This enables GNOME to serve as a tool for multi-messenger astronomy. The algorithm employs a model-agnostic excess-power method to identify network-wide candidate events to be subjected to a model-dependent generalized likelihood-ratio test to determine their statistical significance. We perform the first search with this technique on GNOME data coincident with the binary black hole merger S200311bg detected by LIGO/Virgo on the 11th of March 2020 and find no significant events. We place the first lab-based limits on combinations of ELF production and coupling parameters.

Dark matter substructures emerge naturally in a scenario in which the axion angular field acquires propagating degrees of freedom in a post-inflationary Universe. The DALI experiment is a new generation wavy dark matters interferometer currently in prototyping. Although DALI's main objective is to explore the virialized DM in our Galaxy, to a large degree in this article we explore the prospect for detection of fine grained streams made of axions that would enter the Solar System, as suggested by previous work. We find that DALI will have a sensitivity to encounters with these coherent objects that fully spans the window defined by the coupling strength to photons of representative axion models over a stacked bandwidth of two decades in mass., Comment: 4 pages, 2 figures, 1 table

Anti-quark nuggets (AQNs) have been suggested to solve the dark matter (DM) and the missing antimatter problem in the universe and have been proposed as an explanation of various observations. Their size is in the {\mu}m range and their density is about equal to the nuclear density with an expected flux of about $0.4 / km^2 / year$. For the typical velocity of DM constituents ($\sim$250 km/s), the solar system bodies act as highly performing gravitational lenses. Here we assume that DM streams or clusters are impinging, e.g., on the Earth, as it was worked out for DM axions and Weakly Interacting Massive Particles (WIMPs). Interestingly, in the LHC beam, unforeseen beam losses are triggered by so-called Unidentified Falling Objects (UFOs), which are believed to be constituted of dust particles with a size in the {\mu}m range and a density of several orders of magnitude lower than AQNs. Prezeau suggested that streaming DM constituents incident on the Earth should result in jet-like structures ("hairs") exiting the Earth, or a kind of caustics. Such ideas open novel directions in the search for DM. This work suggests a new analysis of the UFO results at the Large Hadron Collider (LHC), assuming that they are eventually, at least partly, due to AQNs. Firstly, a reanalysis of the existing data from the 4000 beam monitors since the beginning of the LHC is proposed, arguing that dust and AQNs should behave differently. The feasibility of this idea has been discussed with CERN accelerator people and potential collaborators., Comment: 4 pages

We are investigating the possible origin of small-scale anomalies, like the annual stratospheric temperature anomalies. Unexpectedly within known physics, their observed planetary "dependency", does not match concurrent solar activity, whose impact on the atmosphere is unequivocal; this points at an additional energy source of exo-solar origin. A viable concept behind such observations is based on possible gravitational focusing by the Sun and its planets towards the Earth of low-speed invisible streaming matter; its influx towards the Earth gets temporally enhanced. Only a somehow "strongly" interacting invisible streaming matter with the small upper atmospheric screening can be behind the observed temperature excursions. Ordinary dark matter (DM) candidates like axions or WIMPs, cannot have any noticeable impact. The associated energy deposition is $\mathcal{O}(\sim 1000\, \mathrm{GeV}/{{\mathrm{cm}}^2}/\mathrm{sec})$. The atmosphere has been uninterruptedly monitored for decades. Therefore, the upper atmosphere can serve as a novel (low-threshold) detector for the dark Universe, with built-in spatiotemporal resolution while the solar system gravity acts temporally as a signal amplifier. Interestingly, the anomalous ionosphere shows a relationship with the inner earth activity like earthquakes. Similarly investigating the transient sudden stratospheric warmings within the same reasoning, the nature of the assumed "invisible streams" could be deciphered., Comment: 8 pages, 7 figures, Published in the proceedings of the "15th International Conference on Meteorology, Climatology and Atmospheric Physics (COMECAP 2021)" see https://www.conferre.gr/allevents/comecap2020/Proceedings_Final.pdf

Earth can act as a transducer to convert ultralight bosonic dark matter (axions and hidden photons) into an oscillating magnetic field with a characteristic pattern across its surface. Here we describe the first results of a dedicated experiment, the Search for Non-Interacting Particles Experimental Hunt (SNIPE Hunt), that aims to detect such dark-matter-induced magnetic-field patterns by performing correlated measurements with a network of magnetometers in relatively quiet magnetic environments (in the wilderness far from human-generated magnetic noise). Our experiment constrains parameter space describing hidden-photon and axion dark matter with Compton frequencies in the 0.5-5.0 Hz range. Limits on the kinetic-mixing parameter for hidden-photon dark matter represent the best experimental bounds to date in this frequency range., Comment: 22 pages, 12 figures. Accepted for publication in PRD. Minor changes in text and updated / improved limits

Numerous observations suggest that there exist undiscovered beyond-the-Standard-Model particles and fields. Because of their unknown nature, these exotic particles and fields could interact with Standard Model particles in many different ways and assume a variety of possible configurations. Here we present an overview of the Global Network of Optical Magnetometers for Exotic physics searches (GNOME), our ongoing experimental program designed to test a wide range of exotic physics scenarios. The GNOME experiment utilizes a worldwide network of shielded atomic magnetometers (and, more recently, comagnetometers) to search for spatially and temporally correlated signals due to torques on atomic spins from exotic fields of astrophysical origin. We survey the temporal characteristics of a variety of possible signals currently under investigation such as those from topological defect dark matter (axion-like particle domain walls), axion-like particle stars, solitons of complex-valued scalar fields (Q-balls), stochastic fluctuations of bosonic dark matter fields, a solar axion-like particle halo, and bursts of ultralight bosonic fields produced by cataclysmic astrophysical events such as binary black hole mergers., Comment: 22 pages, 12 figures, submitted to Annalen der Physik

Proceedings for our meeting ``What comes beyond the Standard Models'', which covered a broad series of subjects., Comment: This is the proceedings for the 25th Workshop in Bled for "What comes beyond the Standard Models'' including also a webinar "meeting'' using Cosmovia on the same subject

The axion dark matter echo technique, proposed in Ref. [1], aims to search for axion dark matter by detecting the electromagnetic echo coming from stimulated decay of ambient axion dark matter interacting with a radio-microwave outgoing beam. In this work we consider deviations from the standard halo model (SHM) in the form of fine grained streams that are present in the solar system and use them as a target for the axion echo method, which demonstrates to be very sensitive to particular local axion dark matter phase space distributions. We show that the extremely small dispersion of the streams works in favor of the echo method performance, improving its sensitivity in the axion-photon coupling up to two orders of magnitude, with respect to the isotropic SHM. We also discuss the possibility of targeting high density dark matter hairs formed when fine grained streams focus by the inner Earth's gravitational field., Comment: 9 pages, 4 figures. Any critical feedback the next two weeks is welcomed

Cosmological simulations for cold dark matter (DM) indicate that a large number of streams might exist in our Galaxy. The present work incorporates gravitational focusing (GF) effects on streaming DM constituents by the Sun and the Earth preceding their encounter with Earth bound detectors. For streaming DM, the GF gives rise to spatiotemporal flux enhancements of orders of magnitude above the nominal DM density. Remarkably, due to Earth's rotation the derived flux enhancements appear as transient signals lasting about 10 seconds repeating daily for days or weeks. This work presents a novel opportunity for DM signal detection and identification, and the present simulation can be applied to any kind of invisible matter entering the solar system.

Dark matter (DM) comes from long-range gravitational observations, and it is considered as something that does not interact with ordinary matter or emits light. However, also on much smaller scales, a number of unexpected observations of the solar activity and the dynamic Earth atmosphere might arise from DM contradicting the aforementioned DM picture. Because, gravitational (self) focusing effects by the Sun or its planets of streaming DM fit as the interpretation of the otherwise puzzling 11-year solar cycle, the mysterious heating of the solar corona, atmospheric transients, etc. Observationally driven, an external impact by overlooked streaming invisible matter reconciles the investigated mysterious behavior showing otherwise unexpected planetary relationships; this is a signature for gravitational focusing of streaming DM by the solar system bodies. Then, focusing of DM streams could also occur in exoplanetary systems, suggesting for the first time the carrying out of investigations by searching for the associated stellar activity as a function of the exoplanetary orbital phases., Comment: 7 pages, 2 figures, Presented at the first Electronic Conference on Universe, February 2021

We investigate the prospects for direct detection of Dark Matter (DM) particles, such as dark photons, incident on the upper atmosphere. A recent work relates the burst-like temperature excursions in the stratosphere at heights of ~38-47 km with incident invisible streaming matter. Surprisingly, dark photons match the reasoning presented in that work provided they constitute part of the local DM density. Dark photons mix with real photons with the same total energy without the need for an external field as would be required for instance for axions. Furthermore, the ionospheric plasma column above the stratosphere can enhance the dark photon to photon conversion due to resonance. The stratosphere is easily accessible via balloon flights. Balloon missions with up to a few tons of payload can be readily assembled to operate for 1-2 months at such atmospheric heights making for realistic short term endeavor of on-site direct DM search following this proposal. The approach need not be limited to streaming dark photons as other DM candidates might be searched simultaneously. Combining different types of measurements in a multi-band detector system and/or relating such investigations with other concurrent atmospheric observations, e.g. from space, may be proven to be the missing new approach in direct DM detection.

The main alternatives of the recent XENON1T observation are solar axions, neutrino magnetic moment and tritium. In this short note we suggest to crosscheck whether the observation is related or not to dark matter (DM) streams, by searching for planetary dependence of the observed excess. If such a correlation is derived, this hint (<3.5sigma) can become the overlooked direct DM discovery. To do this it is necessary to analyze the time distribution of all the XENON1T data, and in particular the electronic events with their time stamp and energy. Notably, the velocities of the dark sector allow for planetary focusing effects towards the earth either by a single celestial body or combined by the whole solar system. Surprisingly, as yet this possibility has not been applied in the field of direct dark matter search, even though DM velocities fit-in well planetary gravitational lensing effects. The widely used signature of a direct dark matter search needs to be redefined, while, with luck, such an analysis might confirm or exclude the solar origin of the observed excess. Therefore, we suggest that XENON1T and DAMA release the data., Comment: 1 page

We have performed a search for CPT violation in neutral charm meson oscillations using data from the FOCUS Experiment. While flavor mixing in the charm sector is predicted to be small by the Standard Model, it is still possible to investigate CPT violation through a study of the proper time dependence of a CPT asymmetry in right-sign decay rates for $D^0\to K^-\pi^+$ and $\d0b\to K^+\pi^-$. This asymmetry is related to the CPT violating complex parameter $\xi$ and the mixing parameters $x$ and $y$: $A_{CPT}\propto{\rm Re} \xi y-{\rm Im} \xi x$. Our 95% confidence level limit is $-0.0068<{\rm Re} \xi y-{\rm Im} \xi x<0.0234$. Within the framework of the Standard Model Extension incorporating general CPT violation, we also find 95% confidence level limits for the expressions involving coefficients of Lorentz violation. We present measurements of the \lb lifetime in the exclusive decay channel \lbdec with $J/\psi \to \mu^+ \mu^-$ and $\Lambda \to p \pi^-$, the $B^0$ lifetime in the decay \bddecks with $J/\psi \to mu^+ \mu^-$ and $K^0_{S} \to \pi^+ \pi^-$, and the ratio of these lifetimes. The analysis is based on approximately 225 pb$^{-1}$ of data recorded with the D{\O}detector in $p bar{p}$ collisions at $\sqrt{s} =1.96$ TeV. The \lb lifetime is determined to be $\tau(\Lambda^0_b) = 1.36 \pm 0.3 ps$, the $B^0$ lifetime $\tau(\Lambda^0_b) = 1.43 \pm 0.12 ps$, and the ratio $\fr ac{\tau(\Lambda_b)}{\tau(B_d)}=0.95\pm0.22$. In contrast with previous measurements using semileptonic decays, this is the first determination of the \lb lifetime based on a fully reconstructed decay channel., Comment: 166 pages, PhD Thesis