Temporal and energy characteristics of the very-high-energy gamma-ray bursts from evaporating primordial black holes have been calculated by assuming that the photospheric and chromospheric effects ...are negligible. The technique of searching for such bursts on shower arrays is described. We show that the burst time profile and the array dead time should be taken into account to interpret experimental data. Based on data from the Andyrchy array of the Baksan Neutrino Observatory (Institute for Nuclear Research, Russian Academy of Sciences), we have obtained an upper limit on the number density of evaporating primordial black holes in a local region of space with a scale size of ∼10
−3
pc. Comparison with the results of previous experiments is made.
The ARIANNA experiment seeks to observe the diffuse flux of neutrinos in the 108–1010GeV energy range using a grid of radio detectors at the surface of the Ross Ice Shelf of Antarctica. The detector ...measures the coherent Cherenkov radiation produced at radio frequencies, from about 100MHz–1GHz, by charged particle showers generated by neutrino interactions in the ice. The ARIANNA Hexagonal Radio Array (HRA) is being constructed as a prototype for the full array. During the 2013–14 austral summer, three HRA stations collected radio data which was wirelessly transmitted off site in nearly real-time. The performance of these stations is described and a simple analysis to search for neutrino signals is presented. The analysis employs a set of three cuts that reject background triggers while preserving 90% of simulated cosmogenic neutrino triggers. No neutrino candidates are found in the data and a model-independent 90% confidence level Neyman upper limit is placed on the all flavor ν+ν¯ flux in a sliding decade-wide energy bin. The limit reaches a minimum of 1.9×10-23GeV-1cm-2s-1sr-1 in the 108.5–109.5GeV energy bin. Simulations of the performance of the full detector are also described. The sensitivity of the full ARIANNA experiment is presented and compared with current neutrino flux models.
Extragalactic background of high energy neutrinos arising from the interactions of cosmic ray protons with far-infrared extragalactic background radiation is calculated. The main assumption is that ...the cosmic ray spectrum at energies higher than 10
8
GeV has extragalactic origin and, therefore, is proton dominated. All calculations are performed with taking into account the possible cosmological evolution of extragalactic sources of cosmic ray protons as well as infrared-luminous galaxies.
We show that nucleon electromagnetic structure functions of deep inelastic scattering in Regge-Gribov limit (fixed Q-squared, asymptotically large 1/x and s) can be well described in the ...two-component (soft + hard) approach. In the concrete model elaborated by authors, the soft part of the virtual photon-nucleon scattering is given by the vector meson dominance, with taking into account the radial excitations of the rho-meson and nondiagonal transitions in meson-nucleon interactions. The hard part is calculated by using the dipole factorization, i.e., the process is considered as the dissociation of the photon into a -pair (the "color dipole") and the subsequent interaction of this dipole with the nucleon. The dipole cross section has a Regge-type s-dependence and vanishes in the limit of large transverse sizes of the dipole. We give the brief description of the model and present results of the detailed comparison of model predictions with experimental data for electromagnetic structure functions of the nucleon.
Dissolution of interstitials leads to an increase of equilibrium concentration of the site vacancies as a result of two main contributions: increase of entropy of solid solution and expenditure of ...energy for injection of the interstitial atoms. After hydrogen outgassing vacancies become thermodynairfically unstable and form dislocation loops which can be detected by means ofTEM. In our opinion, the concept of hydrogen-induced vacancies can be useful for interpretation of hydrogen-induced phase transformations and mechanism of plastic deformation ofhydrogenated materials.
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