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Related papers: Structures in the cosmic ray energy spectra

200 papers

A major feature of the energy spectrum of the cosmic radiation above 10$^{19}$ eV is the increasing fraction of heavy nuclei with respect to light nuclei. This fact, along with other simple assumptions, is adopted to calculate the energy…

High Energy Astrophysical Phenomena · Physics 2017-07-11 Antonio Codino

High-energy cosmic rays, impinging on the atmosphere of the Earth initiate cascades of secondary particles, the extensive air showers. The electrons and positrons in the air shower emit electromagnetic radiation. This emission is detected…

High Energy Astrophysical Phenomena · Physics 2017-05-12 Jörg R. Hörandel , LOFAR key science project Cosmic Rays

The AMS Collaboration has recently released data on cosmic ray (CR) leptons and hadrons that can shed light on two exciting problems in CR physics: on one side, the origin of the rise of the CR positron fraction above ~10 GeV of energy, on…

High Energy Astrophysical Phenomena · Physics 2015-11-02 Nicola Tomassetti

First results of a cosmic-ray electron + positron spectrum, from 10 GeV to 3 TeV, is presented based upon observations with the CALET instrument on the ISS starting in October, 2015. Nearly a half million electron + positron events are…

We review the current status of cosmological parameters, dark energy and large-scale structure, from a theoretical and observational perspective. We first present the basic cosmological parameters and discuss how they are measured with…

Astrophysics · Physics 2007-05-23 S. E. Deustua , R. Caldwell , P. Garnavich , L. Hui , A. Refregier

The positron fraction in cosmic rays was found to be a steadily increasing in function of energy, above $\sim$ 10 GeV. This behaviour contradicts standard astrophysical mechanisms, in which positrons are secondary particles, produced in the…

High Energy Astrophysical Phenomena · Physics 2015-02-25 M. Boudaud , S. Aupetit , S. Caroff , A. Putze , G. Belanger , Y. Genolini , C. Goy , V. Poireau , V. Poulin , S. Rosier , P. Salati , L. Tao , M. Vecchi

Based on general considerations rather than model-dependent fits to specific scenarios, we argue that an increase with energy of the positron fraction in cosmic rays, suggested by several experiments at E>~7 GeV, most likely requires a…

High Energy Physics - Phenomenology · Physics 2010-04-21 Pasquale Dario Serpico

Detecting any evolution of dimensionless in the ratios of physical quantities, such as the fine structure constant, would prove that the Weak Equivalence Principle is violated and lead to a paradigm shift in physics. High resolution…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-03 Dinko Milaković

We present the results of new calculations of the energy spectra of cosmic ray electrons, positrons and also positron fraction under assumption that both electrons and positrons are generated by the same Galactic sources, which accelerate…

High Energy Astrophysical Phenomena · Physics 2019-05-17 Nikolay Volkov , Anatoly Lagutin , Alexander Tyumentsev

Analytical calculations of extra-galactic cosmic ray spectra above ~10^17 eV are often performed assuming continuous source distributions, giving rise to spectra that depend little on the propagation mode, be it rectilinear or diffusive. We…

Astrophysics · Physics 2008-11-26 Guenter Sigl

The fine structure constant, $\alpha$, sets the strength of the electromagnetic force. The Standard Model of particle physics provides no explanation for its value, which could potentially vary. The wavelengths of stellar absorption lines…

Solar and Stellar Astrophysics · Physics 2022-11-30 Michael T. Murphy , Daniel A. Berke , Fan Liu , Chris Flynn , Christian Lehmann , Vladimir A. Dzuba , Victor V. Flambaum

We calculate the energy spectra and mass composition of cosmic rays in energy region 1 - 10^8 GeV/particle under the assumption that cosmic rays propagation in the Galaxy is described by anomalous diffusion equation. Our results and…

Astrophysics · Physics 2007-05-23 A. A. Lagutin , D. V. Strelnikov , A. G. Tyumentsev

Cosmic ray nuclei, cosmic ray electrons with energy above a few GeV, and the diffuse gamma-ray background radiation (GBR) above a few MeV, presumed to be extragalactic, could all have their origin or residence in our galaxy and its halo.…

Astrophysics · Physics 2007-05-23 Arnon Dar , A. De Rújula , Nikos Antoniou

Measurement of the chemical and isotopic composition of cosmic rays is essential for the precise understanding of their propagation in the galaxy. While the model parameters are mainly determined using the B/C ratio, the study of extended…

High Energy Astrophysical Phenomena · Physics 2011-01-11 01 Collaboration

A calculation based on flat spacetime symmetries shows how there can be two quantum phases. For one, extreme phase change determines a conventional classical trajectory and four-momentum, i.e. mass times four-velocity. The other phase…

Astrophysics · Physics 2008-01-05 Richard Shurtleff

It is proposed a new approach for estimating the composition of cosmic rays. It is found that the zenith angle distributions and muon components of EAS for energies E>10^19 eV and E>4.10^19 eV differ from each other. It is shown that the…

The composition of the overall spectrum of cosmic rays (CRs) is studied under the assumption that ultra high energy CRs above the energy 10^{17} eV are produced at the shock created by the expanding cocoons around active galactic nuclei…

High Energy Astrophysical Phenomena · Physics 2011-02-11 E. G. Berezhko

A spectrum of cosmic rays within energy range 10^15 - 3x10^17 eV was derived from the data of the small Cherenkov setup, which is a part of the Yakutsk complex EAS array. In this, work a new series of observation is covered. These…

High Energy Astrophysical Phenomena · Physics 2015-06-03 S. P. Knurenko , A. Sabourov

The highest energy cosmic rays observed possess macroscopic energies and their origin is likely to be associated with the most energetic processes in the Universe. Their existence triggered a flurry of theoretical explanations ranging from…

High Energy Physics - Phenomenology · Physics 2014-11-17 Guenter Sigl