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Related papers: Unparticle effects on cosmic ray photon and $e^\pm…

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It has recently been suggested that a scale invariant "unparticle" sector with a non-trivial infrared fixed point may couple to the Standard Model (SM) via higher dimensional operators. The weakness of such interactions hides the the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Hooman Davoudiasl

We discuss effects of two-photon exchange (TPE) in various observables of the elastic ep-scattering. The imaginary part of the TPE amplitude manifests in target and beam normal spin asymmetries. The real part contributes to the…

High Energy Physics - Phenomenology · Physics 2008-12-03 A. P. Kobushkin , D. L. Borisyuk

We consider the one-photon annihilation mechanism in a electron - positron quasiparticle plasma (EPP) created from the vacuum in a strong subcritical laser field due to the dynamical Schwinger mechanism. On the basis of a kinetic theory…

Plasma Physics · Physics 2011-07-26 D. B. Blaschke , G. Röpke , S. M. Schmidt , S. A. Smolyansky , A. V. Tarakanov

We compute the energy spectrum of photons and neutrinos produced by the unwinding of a scaling distribution of cosmic textures, and discuss the implications for the spectrum of high energy cosmic rays, and for CMB spectral distortions.…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-30 Robert Brandenberger , Bryce Cyr , Hao Jiao

The spin effect of electrons/positrons ($e^-$/$e^+$) and polarization effect of $\gamma$ photons are investigated in the interaction of two counter-propagating linearly polarized 10-PW-class laser pulses with a thin foil target. The…

We analyze the electromagnetic scattering of massive particles with and without spin and, using the techniques of effective field theory, we isolate the leading long distance effects beyond one photon exchange, both classical and quantum…

High Energy Physics - Phenomenology · Physics 2008-02-07 Barry R. Holstein , Andreas Ross

We perform a global fit on parity-conserving electron-quark interactions via spin-1 unparticle exchange. Besides the peculiar features of unparticle exchange due to non-integral values for the scaling dimension d_U and a non-trivial phase…

High Energy Physics - Phenomenology · Physics 2011-04-20 Chun-Fu Chang , Kingman Cheung , Tzu-Chiang Yuan

We consider emission of a photon by an electron in the field of a strong laser wave. A probability of this process for circularly or linearly polarized laser photons and for arbitrary polarization of all other particles is calculated. We…

High Energy Physics - Phenomenology · Physics 2007-05-23 D. Yu. Ivanov , G. L. Kotkin , V. G. Serbo

In this paper we present a comprehensive study of the heavy quark production in ultra high energy cosmic ray interactions in the atmosphere considering that the primary cosmic ray can be either a photon, neutrino or a proton. The analysis…

High Energy Physics - Phenomenology · Physics 2014-07-18 V. P. Goncalves , D. R. Gratieri

The standard theory of electromagnetic cascades onto a photon background predicts a quasi-universal shape for the resulting non-thermal photon spectrum. This has been applied to very disparate fields, including non-thermal big bang…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-05 Vivian Poulin , Pasquale D. Serpico

This paper explores the effects of strong magnetic fields on the Compton scattering of relativistic electrons. Recent studies of upscattering and energy loss by relativistic electrons that have used the non-relativistic, magnetic Thomson…

In this paper, we study the effects of the unparticles on the parity-violating asymmetry for the low energy electron-electron scattering, $e^-e^-\to e^-e^-$. Using the data from the E158 experiment at SLAC we extract the limits on the…

High Energy Physics - Phenomenology · Physics 2009-02-23 K. O. Ozansoy

We discuss the effects of diffusion of high energy cosmic rays in turbulent extra-galactic magnetic fields. We find an approximate expression for the low energy suppression of the spectrum of the different mass components (with charge $Z$)…

High Energy Astrophysical Phenomena · Physics 2015-06-16 Silvia Mollerach , Esteban Roulet

We calculated two--photon exchange effects for elastic electron--proton scattering at high momentum transfers. The corresponding nucleon Compton amplitude is defined by two space--like virtual photons that appear to have significant…

High Energy Physics - Phenomenology · Physics 2017-08-23 Andrei Afanasev , Igor Akushevich , N. P. Merenkov

We describe the results of a hybrid matrix--Monte Carlo calculation of cascading of UHE cosmic rays and $\gamma$-rays through the cosmic background radiation fields over cosmological distances. We calculate the $\gamma$-ray and neutrino…

Astrophysics · Physics 2009-10-28 R. J. Protheroe , P. A. Johnson

This paper summarizes the limits on propagation of ultra high energy particles in the Universe, set up by their interactions with cosmic background of photons and neutrinos. By taking into account cosmic evolution of these backgrounds and…

High Energy Astrophysical Phenomena · Physics 2018-01-24 R. Ruffini , G. V. Vereshchagin , S. -S. Xue

There is an observational correlation between astrophysical shocks and non-thermal particle distributions extending to high energies. As a first step toward investigating the possible feedback of these particles on the shock at the…

High Energy Astrophysical Phenomena · Physics 2012-01-31 Thomas Stroman , Martin Pohl , Jacek Niemiec , Antoine Bret

We have considered the di-photon production with unparticle at LHC. The contributions of spin-0 and spin-2 unparticle to the di-photon production are studied in the invariant mass and other kinematical distributions, along with their…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. C. Kumar , Prakash Mathews , V. Ravindran , Anurag Tripathi

In this work we estimate the heavy quark production in the interaction of ultra high energy cosmic rays in the atmosphere, considering that the primary cosmic ray is a proton or a photon. At these energies the saturation momentum Q_{sat}^2…

High Energy Physics - Phenomenology · Physics 2010-10-27 V. P. Goncalves , M. V. T. Machado

The significant attenuation of the cosmic-ray flux above $\sim 5 10^{19}$ eV suggests that the observed high-energy spectrum is shaped by the so-called GZK effect. This interaction of ultra-high-energy cosmic rays (UHECRs) with the ambient…

Astrophysics · Physics 2010-01-28 D. Allard , N. G Busca , G. Decerprit , A. V. Olinto , E. Parizot