The ADMX collaboration gathered data for its Run 1A axion dark matter search from January to June 2017, scanning with an axion haloscope over the frequency range 645-680 MHz (2.66-2.81 μeV in axion ...mass) at DFSZ sensitivity. The resulting axion search found no axion-like signals comprising all the dark matter in the form of a virialized galactic halo over the entire frequency range, implying lower bound exclusion limits at or below DFSZ coupling at the 90% confidence level. This paper presents expanded details of the axion search analysis of Run 1A, including review of relevant experimental systems, data-taking operations, preparation and interpretation of raw data, axion search methodology, candidate handling, and final axion limits.
We present an apparatus for detection of cyclotron radiation yielding a frequency-based β± kinetic energy determination in the 5 keV to 2.1 MeV range, characteristic of nuclear β decays. The ...cyclotron frequency of the radiating β particles in a magnetic field is used to determine the β energy precisely. Our work establishes the foundation to apply the cyclotron radiation emission spectroscopy (CRES) technique, developed by the Project 8 Collaboration, far beyond the 18-keV tritium endpoint region. We report initial measurements of β–’s from 6He and β+’s from 19Ne decays to demonstrate the broadband response of our detection system and assess potential systematic uncertainties for β spectroscopy over the full (MeV) energy range. To our knowledge, this is the first direct observation of cyclotron radiation from individual highly relativistic β’s in a waveguide. Furthermore, this work establishes the application of CRES to a variety of nuclei, opening its reach to searches for new physics beyond the TeV scale via precision β-decay measurements.
Project 8 has developed a novel technique, cyclotron radiation emission spectroscopy (CRES), for direct neutrino mass measurements. A CRES-based experiment on the beta spectrum of tritium has been ...carried out in a small-volume apparatus. Here, we provide a detailed account of the experiment, focusing on systematic effects and analysis techniques. In a Bayesian (frequentist) analysis, we measure the tritium endpoint as ${18}$ ${553}_{—19}^{+18}$ (${18}$ ${548}_{—19}^{+19}$) eV and set upper limits of 155 (152) eV (90% C.L.) on the neutrino mass. No background events are observed beyond the endpoint in 82 days of running. We also demonstrate an energy resolution of 1.66 ± 0.19 eV in a resolution-optimized magnetic trap configuration by measuring 83mKr 17.8-keV internal-conversion electrons. These measurements establish CRES as a low-background, high-resolution technique with the potential to advance neutrino mass sensitivity
The Axion Dark Matter eXperiment (ADMX) has previously excluded Dine-Fischler-Srednicki- Zhitnisky (DFSZ) axions between 680-790 MHz under the assumption that the dark matter is described by the ...isothermal halo model. However, the precise nature of the velocity distribution of dark matter is still unknown, and alternative models have been proposed. Here, we report the results of a non-virialized axion search over the mass range 2.81–3.31 µeV, corresponding to the frequency range 680–800 MHz. This analysis marks the most sensitive search for non-virialized axions sensitive to Doppler effects in the Milky Way Halo to date. Accounting for frequency shifts due to the detector’s motion through the Galaxy, we exclude cold flow relic axions with a velocity dispersion of $\mathscr{O}$(10-7)c with 95% confidence.
Nonvirialized dark-matter axions may be present in the Milky Way halo in the form of low-velocity-dispersion flows. The Axion Dark-Matter eXperiment performed a search for the conversion of these ...axions into microwave photons using a resonant cavity immersed in a strong, static magnetic field. The spread of photon energy in these measurements was measured at spectral resolutions of the order of 1 Hz and below. If the energy variation were this small, the frequency modulation of any real axion signal due to the orbital and rotational motion of Earth would become non-negligible. Conservative estimates of the expected signal modulation were made and used as a guide for the search procedure. The photon frequencies covered by this search are 812–852 and 858–892 MHz, which correspond to an axion mass of 3.36–3.52 and 3.55–3.69 μeV. No axion signal was found, and limits were placed on the maximum local density of nonvirialized axions of these masses.
Epidemiological researches, carried out by professor A.A. Shain in Ob-Irtysh basin of Tyumen region, have allowed to consider chronic opisthorchiasis as facultative liver precancer and develop the ...original concept of cholangiocarcinogenesis on the background of long-term invasion by trematode Opisthorchis felineus of hepatobiliary system of the body. According to this concept, the initiating role in cholangiocyte transformation belongs to endogenous factors secondary bile acids, having mutagenic/carcinogenic properties, which formation is mediated by helminthosis-related exogenous intestinal microflora in intrahepatic bile ducts. Obtained data confirmed content of endogenous carcinogenic factors secondary bile acids in duct bile of chronic opistorchosis patients. Cholestasis, caused by long-term parasitization of helminth Opisthorchis felineus in hepatobiliary system of the body, mediates formation of the host promoter factors, contributing to cholangiocarcinoma progression. These include: high concentration in duct bile of bile acids, products of helminths activity and lipid peroxidation of somatic cell membranes. Promoter factors of cholangiocanerogenesis are also disorders of cholangiocyte membranes structure, tissue regulation of their regeneration, DNA repair and anti-tumorigenic protection of the body. The results of the study confirm the concept of occurrence and development of the process of cholangiocarcinogenesis in chronic opistorchosis infestation, proposed by Professor A.A. Shain and allow to reasonably develop approaches to the correction of homeostasis regulation systems of the organism in the specified helminthiasis. Which also determines the secondary prevention of malignant process in ductal epithelium of hepatobiliary system in posthelminthic period.
This Letter reports results from a haloscope search for dark matter axions with masses between 18 2.66 and 2.81 eV. The search excludes the range of axion-photon couplings predicted by plausible 19 ...models of the invisible axion. This unprecedented sensitivity is achieved by operating a large-volume 20 haloscope at sub-Kelvin temperatures, thereby reducing thermal noise as well as the excess noise 21 from the ultra-low-noise SQUID amplier used for the signal power readout. Ongoing searches will 22 provide nearly denitive tests of the invisible axion model over a wide range of axion masses.
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