English
Related papers

Related papers: Annihilation-Gamma-based Diagnostic Techniques for…

200 papers

Decay rates of the positronium molecule $\text{Ps}_{2}$ into two photons and into an electron-positron pair are determined. Previous studies find that these rates are very different, \[ \Gamma\left(\text{Ps}_{2}\to…

High Energy Physics - Phenomenology · Physics 2021-11-04 M. Jamil Aslam , Wen Chen , Andrzej Czarnecki , Samiur Rahman Mir , Muhammad Mubasher

In the past decade, gamma-ray observations and radio observations put strong constraints on the parameters of dark matter annihilation. In this article, we suggest another robust way to constrain the parameters of dark matter annihilation.…

High Energy Astrophysical Phenomena · Physics 2017-08-09 Man Ho Chan

The beaming pattern of thermal annihilation radiation is broader than the beaming pattern produced by isotropic nonthermal electrons and positrons in the jets of radio-emitting active galactic nuclei which Compton scatter photons from an…

Astrophysics · Physics 2009-10-30 J. G. Skibo , C. D. Dermer , R. Schlickeiser

The Galaxy hosts a widespread population of low-energy positrons revealed by successive generations of gamma-ray telescopes through a bright annihilation emission from the bulge region, with a fainter contribution from the inner disk. The…

High Energy Astrophysical Phenomena · Physics 2015-06-05 P. Martin , A. W. Strong , P. Jean , A. Alexis , R. Diehl

When a cylindrically-symmetric magnetized plasma compresses or expands, velocity-space anisotropy is naturally generated as a result of the different adiabatic conservation laws parallel and perpendicular to the magnetic field. When the…

Plasma Physics · Physics 2023-05-18 Ian E. Ochs , Nathaniel J. Fisch

Recent results from the PAMELA experiment indicate an excess in the positron spectrum above 10 GeV, but anti-proton data are consistent with the expected astrophysical backgrounds. We propose a scenario that reproduces these features. Dark…

High Energy Physics - Phenomenology · Physics 2009-09-24 Daniel J. Phalen , Aaron Pierce , Neal Weiner

We are developing a positron-electron plasma trap based on a dipole magnetic field generated by a levitated superconducting magnet to investigate the physics of magnetized plasmas with mass symmetry as well as antimatter components. Such…

Plasma Physics · Physics 2023-04-04 Naoki Sato

Particle acceleration and pitch-angle anisotropy resulting from magnetic reconnection are investigated in highly magnetized ion-electron plasmas. By means of fully kinetic particle-in-cell simulations, we demonstrate that magnetic…

High Energy Astrophysical Phenomena · Physics 2024-08-26 Luca Comisso

Two experiments on the OMEGA Laser System used oblique proton radiography to measure magnetic fields in cylindrical implosions with and without an applied axial magnetic field. Although the goal of both experiments was to measure the…

Dark Matter annihilation (DMA) may yield an excess of gamma rays and antimatter particles, like antiprotons and positrons, above the background from cosmic ray interactions. The excess of diffuse Galactic Gamma Rays from EGRET shows all the…

High Energy Physics - Phenomenology · Physics 2015-05-13 W. de Boer

Results from the Modified Three Gradient Method (MTGM), applied to a pulsed high intensity electron source, are presented. The MTGM makes possible the non-destructive determination of beam emittance in the space charge presence [1]. We…

Accelerator Physics · Physics 2007-05-23 S. Marghitu , C. Oproiu , C. Dinca , O. Marghitu

We analyze the recently published Fermi-LAT diffuse gamma-ray measurements in the context of leptonically annihilating or decaying dark matter (DM) with the aim to explain simultaneously the isotropic diffuse gamma-ray and the PAMELA, Fermi…

High Energy Astrophysical Phenomena · Physics 2014-11-20 Gert Hütsi , Andi Hektor , Martti Raidal

A relativistic electron-positron beam propagating through a magnetized electron-ion plasma is shown to generate both circularly and linearly polarized synchrotron radiation. The degrees of circular and linear polarizations depend both on…

Plasma Physics · Physics 2019-05-29 Ujjwal Sinha , Christoph H. Keitel , Naveen Kumar

We report a systematic first principles study on positron annihilation parameters in the $\beta$-Ga$_2$O$_3$ lattice and Ga mono-vacancy defects complemented with orientation-dependent experiments of the Doppler broadening of the…

Parallel thermal conduction along stochastic magnetic field lines may be reduced because the heat conducting electrons become trapped and detrapped between regions of strong magnetic field (magnetic mirrors). The problem reduces to a simple…

Astrophysics · Physics 2009-10-31 Leonid Malyshkin , Russell Kulsrud

We describe electron-positron pairs creation around an electrically charged star core collapsing to an electromagnetic black hole (EMBH), as well as pairs annihilation into photons. We use the kinetic Vlasov equation formalism for the pairs…

Astrophysics · Physics 2017-08-23 R. Ruffini , L. Vitagliano , S. -S. Xue

A fully relativistic treatment of Bernstein waves in an electron-positron pair plasma has remained too formidable a task owing to the very complex nature of the problem. In this article, we perform contour integration of the dielectric…

Plasma Physics · Physics 2009-11-19 Ramandeep Gill , Jeremy S. Heyl

Some of the most stringent constraints on physics beyond the Standard Model (BSM) arise from considerations of particle emission from astrophysical plasmas. However, many studies assume that particle production occurs in an isotropic plasma…

High Energy Physics - Phenomenology · Physics 2024-10-22 Nirmalya Brahma , Katelin Schutz

The rise in the energy spectrum of the positron ratio, observed by the PAMELA satellite above 10 GeV, and other cosmic ray measurements, have been interpreted as a possible signature of Dark Matter annihilation in the Galaxy. However, the…

High Energy Astrophysical Phenomena · Physics 2014-11-18 Miguel Pato , Lidia Pieri , Gianfranco Bertone

It is difficult to discover pulsars via their gamma-ray emission because current instruments typically detect fewer than one photon per million rotations. This creates a significant computing challenge for isolated pulsars, where the…

High Energy Astrophysical Phenomena · Physics 2020-10-23 L. Nieder , B. Allen , C. J. Clark , H. J. Pletsch