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  • Stopping muon effect and estimation of intracloud electric field
    Astropart. Phys. (IF 2.61) Pub Date : 2020-08-07
    A. Chilingarian; G. Hovsepyan; G. Karapetyan; M. Zazyan

    Employing large thunderstorm ground enhancements (TGEs) as a manifestation of the strong electric field in thundercloud we measure fluxes of almost all species of secondary cosmic rays to estimate the strength of the intracloud electric field. The modulation that electric field poses on charged particle flux gives a sizable change in count rate of detectors measuring high energy muon flux and inclined

  • Local interstellar spectra and solar modulation of cosmic ray electrons and positrons
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-25
    Cheng-Rui Zhu; Qiang Yuan; Da-Ming Wei

    Low energy cosmic rays are modulated by the solar activity when they propagation in the heliosphere, leading to ambiguities in understanding their acceleration at sources and propagation in the Milky Way. By means of the precise measurements of the e−, e+, e−+e+, and e+/(e−+e+) spectra by AMS-02 near the Earth, as well as the very low energy measurements of the e−+e+ fluxes by Voyager-1 far away from

  • Hawking radiation screening and shielding in Kerr-Newman and charged accelerating black holes
    Astropart. Phys. (IF 2.61) Pub Date : 2020-08-04
    Usman A. Gillani; Khalid Saifullah

    The dynamics of massive particles near the horizons of charged rotating and charged accelerating black holes is studied. This is done, in particular, from the point of view of studying the screening effect of Hawking radiation and shielding of the Penrose process for these two black holes. We do this by identifying the forbidden regions which are the regions where the particles have negative kinetic

  • Radiative transport of relativistic species in cosmology
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-25
    Cyril Pitrou

    We review the general construction of distribution functions for gases of fermions and bosons (photons), emphasizing the similarities and differences between both cases. The central object which describes polarization for photons is a tensor-valued distribution function, whereas for fermions it is a vector-valued one. The collision terms of Boltzmann equations for fermions and bosons also possess the

  • Parity in Planck full-mission CMB temperature maps
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-24
    Srikanta Panda; Pavan K. Aluri; Pramoda Kumar Samal; Pranati K. Rath

    In the standard model of cosmology, Cosmic Microwave Background (CMB) sky is expected to preserve spatial symmetries. Following our previous studies, we search for evidence of a parity preference in the latest full-mission CMB temperature maps from ESA’s Planck probe. Specifically, we probe (a)symmetry in power between even and odd multipoles of CMB, that corresponds to a particular parity preference

  • A run-wise simulation and analysis framework for Imaging Atmospheric Cherenkov Telescope arrays
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-07
    M. Holler; J.-P. Lenain; M. de Naurois; R. Rauth; D.A. Sanchez

    We introduce a new simulation and analysis paradigm for Imaging Atmospheric Cherenkov Telescope (IACT) arrays, simulating the actual observation conditions as well as individual telescope configuration for each observation unit. Compared to existing frameworks, where simulations are usually generated using pre-defined settings, this run-wise simulation approach implies more realistic simulations and

  • The low rate of Galactic pevatrons
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-09
    Pierre Cristofari; Pasquale Blasi; Elena Amato

    Although supernova remnants remain the main suspects as sources of Galactic cosmic rays up to the knee, the supernova paradigm still has many loose ends. The weakest point in this construction is the possibility that individual supernova remnants can accelerate particles to the rigidity of the knee, ~ 106 GV. This scenario heavily relies upon the possibility to excite current driven non-resonant hybrid

  • Production of secondary particles in heavy nuclei interactions in supernova remnants
    Astropart. Phys. (IF 2.61) Pub Date : 2020-07-02
    Maulik Bhatt; Iurii Sushch; Martin Pohl; Anatoli Fedynitch; Samata Das; Robert Brose; Pavlo Plotko; Dominique M.-A. Meyer

    Depending on their type, supernova remnants may have ejecta material with high abundance of heavy elements such as carbon or oxygen. In addition, core-collapse supernovae explode in the wind material of their progenitor star that may also have a high abundance of heavy elements. Hadronic collisions in these enriched media spawn the production of gamma rays, neutrinos, and secondary electrons with spectra

  • Search for ultra-high energy photons through preshower effect with gamma-ray telescopes: Study of CTA-North efficiency
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-30
    Kévin Almeida Cheminant; Dariusz Góra; David E. Alvarez Castillo; Aleksander Ćwikła; Niraj Dhital; Alan R. Duffy; Piotr Homola; Konrad Kopański; Marcin Kasztelan; Peter Kovacs; Marta Marek; Alona Mozgova; Vahab Nazari; Michał Niedźwiecki; Dominik Ostrogórski; Karel Smolek; Jarosław Stasielak; Oleksandr Sushchov; Jilberto Zamora-Saa

    As ultra-high energy photons (EeV and beyond) propagate from their sources of production to Earth, radiation-matter interactions can occur, leading to an effective screening of the incident flux. In this energy domain, photons can undergo e+/e− pair production when interacting with the surrounding geomagnetic field, which in turn can produce a cascade of electromagnetic particles called preshower.

  • Modelling the broadband emission from the white dwarf binary system AR Scorpii
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-24
    K.K. Singh; P.J. Meintjes; Q. Kaplan; F.A. Ramamonjisoa; S. Sahayanathan

    AR Scorpii is a compact binary system which consists of a magnetic white dwarf and an M-type main sequence cool star. This binary system was discovered as a source of pulsating radiation in radio, infrared, optical, ultraviolet and X-ray wavebands. In this work, we have analyzed the γ-ray data in the energy range 100 MeV to 500 GeV from the Fermi-Large Area Telescope (LAT) observations for the period

  • Reconstructing air shower parameters with LOFAR using event specific GDAS atmosphere
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-01
    P. Mitra; A. Bonardi; A. Corstanje; S. Buitink; G.K Krampah; H. Falcke; B.M. Hare; J.R. Hörandel; T. Huege; K. Mulrey; A Nelles; J.P. Rachen; L. Rossetto; O. Scholten; S. ter Veen; T.N.G. Trinh; T. Winchen

    The limited knowledge of atmospheric parameters like humidity, pressure, temperature, and the index of refraction has been one of the important systematic uncertainties in reconstructing the depth of the shower maximum from the radio emission of air showers. Current air shower Monte Carlo simulation codes like CORSIKA and the radio plug-in CoREAS use various averaged parameterized atmospheres. However

  • Influence of resonances on the 11B(n,γ)12B capture reaction rate. Capture to the ground state of 12B
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-17
    S.B. Dubovichenko; N.A. Burkova; A.V. Dzhazairov-Kakhramanov; A.S. Tkachenko

    Within the framework of the modified potential cluster model with a classification of orbital states according to Young diagrams, the possibility of describing experimental data for total cross sections of the neutron radiative capture on 11B to the ground state of 12B at energies of 10 meV (1 meV = 10−3 eV) to 7 MeV was considered. It was shown that, taking into account only the E1 transition from

  • On angular resolution limits for air shower arrays
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-15
    Werner Hofmann

    The angular resolution limits achievable for perfect ground-based high-altitude gamma-ray air shower detectors are investigated, to serve as benchmarks for the design of real detectors. A ‘perfect’ detector is assumed to accurately measure impact position, time and energy of all electromagnetic shower particles reaching the ground. The shower direction is determined from a likelihood fit to all measured

  • Simulations of Events for the LUX-ZEPLIN (LZ) Dark Matter Experiment
    Astropart. Phys. (IF 2.61) Pub Date : 2020-06-16
    D.S. Akerib; C.W. Akerlof; A. Alqahtani; S.K. Alsum; T.J. Anderson; N. Angelides; H.M. Araújo; J.E. Armstrong; M. Arthurs; X. Bai; J. Balajthy; S. Balashov; J. Bang; D. Bauer; A. Baxter; J. Bensinger; E.P. Bernard; A. Bernstein; P. Zarzhitsky

    The LUX-ZEPLIN dark matter search aims to achieve a sensitivity to the WIMP-nucleon spin-independent cross-section down to (1–2)×10−12 pb at a WIMP mass of 40 GeV/c2. This paper describes the simulations framework that, along with radioactivity measurements, was used to support this projection, and also to provide mock data for validating reconstruction and analysis software. Of particular note are

  • Prospects on high-energy source searches based on pattern recognition Object detection in the H.E.S.S. Galactic Plane Survey and catalogue cross-matches
    Astropart. Phys. (IF 2.61) Pub Date : 2020-05-07
    Q. Remy; Y.A. Gallant; M. Renaud

    The H.E.S.S. Galactic Plane Survey [HGPS, 1] represents one of the most sensitive surveys of the Galactic Plane at very high energies (VHE, 0.1 < E < 100 TeV). However the source detection algorithm of the HGPS pipeline is not well-suited for complex regions, including sources with shell-like morphologies. As an alternative and complementary approach, we have investigated blind search methods for VHE

  • Higgs inflation with non-minimal derivative coupling to gravity
    Astropart. Phys. (IF 2.61) Pub Date : 2020-05-04
    L.N. Granda; D.F. Jimenez; W. Cardona

    We consider an extension of Higgs inflation in which the Higgs field is non-minimally coupled to gravity through its kinetic term. We analyzed power-law coupling functions with positive or negative integer power and found that the Higgs boson can drive a successful inflation only for the cases n=2,1,0,−1. Theoretical predictions for both tensor to scalar ratio r and scalar spectral index ns are within

  • The SPHERE-2 detector for observation of extensive air showers in 1 PeV – 1 EeV energy range
    Astropart. Phys. (IF 2.61) Pub Date : 2020-05-04
    R.A. Antonov; E.A. Bonvech; D.V. Chernov; T.A. Dzhatdoev; M. Finger; M. Finger; D.A. Podgrudkov; T.M. Roganova; A.V. Shirokov; I.A. Vaiman

    The SPHERE-2 balloon-borne detector designed for extensive air shower (EAS) observations using EAS optical Vavilov-Cherenkov radiation (“Cherenkov light”), reflected from the snow-covered surface of Lake Baikal is described. We briefly discuss the concept behind the reflected Cherenkov light method, characterize the conditions at the experimental site and overview the construction of the tethered balloon

  • Restoration of azimuthal symmetry of muon densities in extended air showers
    Astropart. Phys. (IF 2.61) Pub Date : 2020-04-21
    Nicusor Arsene; Markus Roth; Octavian Sima

    At ground level, the azimuthal distribution of muons in inclined Extensive Air Showers (EAS) is asymmetric, mainly due to geometric effects. Several EAS observables sensitive to the primary particle mass, are constructed after mapping the density of secondary particles from the ground plane to the shower plane (perpendicular to the shower axis). A simple orthogonal projection of the muon coordinates

  • The shape of the cosmic ray proton spectrum
    Astropart. Phys. (IF 2.61) Pub Date : 2020-03-05
    Paolo Lipari; Silvia Vernetto

    Recent observations of cosmic ray protons in the energy range 102–105 GeV have revealed that the spectrum cannot be described by a simple power law. A hardening of the spectrum around an energy of order a few hundred GeV, first observed by the magnetic spectrometers PAMELA and AMS02, has now been confirmed by several calorimeter detectors (ATIC, CREAM, CALET, NUCLEON and DAMPE). These new measurements

  • Anisotropic temperature effects on Landau damping in Kappa–Maxwellian astrophysical plasmas
    Astropart. Phys. (IF 2.61) Pub Date : 2020-03-16
    Mehran Shahmansouri; Myoung-Jae Lee; Young-Dae Jung

    In many physical situations, especially in space, plasmas are found to have anisotropic power-law distributions, i.e., they can have one-dimensional Kappa distribution with high-energy tails in a preferred direction and a Maxwellian distribution perpendicular to it. In this work, we have used this distribution to study the Landau damping of electron-acoustic waves (EAWs) in the Kappa–Maxwellian plasma

  • An analysis method for data taken by Imaging Air Cherenkov Telescopes at very high energies under the presence of clouds
    Astropart. Phys. (IF 2.61) Pub Date : 2020-03-19
    Sobczyńska Dorota; Adamczyk Katarzyna; Sitarek Julian; Szanecki Michał

    The effective observation time of Imaging Air Cherenkov Telescopes (IACTs) plays an important role in the detection of γ-ray sources, especially when the expected flux is low. This time is strongly limited by the atmospheric conditions. Significant extinction of Cherenkov light caused by the presence of clouds reduces the photon detection rate and also complicates or even makes impossible proper data

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