Energy dependence of bound-electron–positron pair production at very-high-energy ion-ion transits

1991 ◽  
Vol 44 (9) ◽  
pp. 5569-5585 ◽  
Author(s):  
A. J. Baltz ◽  
M. J. Rhoades-Brown ◽  
J. Weneser
Keyword(s):  
Pair Production ◽  
Energy Dependence ◽  
High Energy ◽  
Electron Positron ◽  
Very High Energy ◽  
Bound Electron ◽  
Electron Positron Pair ◽  
Very High

scholarly journals VERY HIGH ENERGY GAMMA RAYS FROM e± PAIR HALOS

2009 ◽  
Vol 18 (06) ◽  
pp. 911-927 ◽  
Author(s):  
A. EUNGWANICHAYAPANT ◽  
F. AHARONIAN
Keyword(s):  
Energy Spectrum ◽  
Gamma Rays ◽  
High Energy ◽  
Angular Distributions ◽  
Extragalactic Background Light ◽  
Electron Positron ◽  
Very High Energy ◽  
Energy Gamma ◽  
Electron Positron Pair ◽  
Very High

In this paper we study the formation of giant electron–positron pair halos around the powerful high energy extragalactic sources. We investigate the dependence of radiation of pair halos, in particular the spectral and angular distributions on the energy spectrum of the primary gamma rays, the redshift of the source, and the flux of the extragalactic background light.

π-Meson-Elektron-Streuung und Struktur des π-Mesons

1960 ◽  
Vol 15 (12) ◽  
pp. 1023-1030 ◽  
Author(s):  
H. Salecker
Keyword(s):  
Form Factor ◽  
Cross Sections ◽  
High Energy ◽  
Electromagnetic Structure ◽  
Electron Positron ◽  
Pair Annihilation ◽  
Very High Energy ◽  
Scattering Cross Sections ◽  
Electron Positron Pair ◽  
Very High

In this article we propose π-meson-electron scattering as a possibility for investigating the electromagnetic structure of the pion. This experiment requires very high energy, but not necessarily such a high accuracy as the extrapolation procedure of CHEW and Low. After a short discussion of the general properties of the electromagnetic formfactor of the π-meson, we calculate the π—e and the e—π scattering cross sections with form factor. With an energy of 25 GeV and a 10% experimental error we can probe the root mean square radius of the pion down to 0.8 10-13 cm, with 50 GeV down to 0.6·10-13 cm and with 100 GeV to 0.36·10-13 cm. The rms radius of the pion may be larger than previously assumed, because there exists the possibility of a fairly large π — π interaction. A complementary possibility for investigating the electromagnetic structure of the pion consists in electron-positron pair annihilation with the creation of a π± pair. This process will probe the form factor of the π-meson for timelike arguments.

scholarly journals Resonant Ultrarelativistic Electron–Positron Pair Production by High-Energy Electrons in the Field of an X-ray Pulsar

Universe ◽  
2020 ◽  
Vol 6 (9) ◽  
pp. 132 ◽  
Author(s):  
Georgii K. Sizykh ◽  
Sergei P. Roshchupkin ◽  
Victor V. Dubov
Keyword(s):  
Pair Production ◽  
Threshold Energy ◽  
Structure Constant ◽  
High Energy ◽  
Differential Probability ◽  
X Ray ◽  
Initial Electron ◽  
Ultrarelativistic Electron ◽  
Electron Positron ◽  
Electron Positron Pair

The process of resonant high-energy electron–positron pair production by an ultrarelativistic electron colliding with the field of an X-ray pulsar is theoretically investigated. Resonant kinematics of the process is studied in detail. Under the resonance condition, the intermediate virtual photon in the X-ray pulsar field becomes a real particle. As a result, the initial process of the second order in the fine structure constant effectively reduces into two successive processes of the first order: X-ray-stimulated Compton effect and X-ray-stimulated Breit–Wheeler process. For a high-energy initial electron all the final ultrarelativistic particles propagate in a narrow cone along the direction of the initial electron momentum. The presence of threshold energy for the initial electron which is of order of 100 MeV for 1-KeV-frequency field is shown. At the same time, the energy spectrum of the final particles (two electrons and a positron) highly depends on their exit angles and on the initial electron energy. This result significantly distinguishes the resonant process from the non-resonant one. It is shown that the resonant differential probability significantly exceeds the non-resonant one.

scholarly journals Lorentz Violation Footprints in the Spectrum of High-Energy Cosmic Neutrinos—Deformation of the Spectrum of Superluminal Neutrinos from Electron-Positron Pair Production in Vacuum

Symmetry ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1419 ◽  
Author(s):  
José Manuel Carmona ◽  
José Luis Cortés ◽  
José Javier Relancio ◽  
Maykoll Anthonny Reyes
Keyword(s):  
Pair Production ◽  
Numerical Simulations ◽  
Lorentz Invariance ◽  
Lorentz Violation ◽  
High Energy ◽  
Energy Scale ◽  
Invariance Violation ◽  
Electron Positron ◽  
Lorentz Invariance Violation ◽  
Electron Positron Pair

The observation of cosmic neutrinos up to 2 PeV is used to put bounds on the energy scale of Lorentz invariance violation through the loss of energy due to the production of e + e - pairs in the propagation of superluminal neutrinos. A model to study this effect, which allows us to understand qualitatively the results of numerical simulations, is presented.

scholarly journals Nuclear Adiabatic Effects of Electron-Positron Pairs on the Dynamical Instability of Very-Massive Stars

2021 ◽  
Vol 68 (1 Jan-Feb) ◽  
Author(s):  
Lurwan Garba ◽  
Firas A. Ahmed
Keyword(s):  
Pair Production ◽  
Massive Stars ◽  
Instability Region ◽  
Adiabatic Index ◽  
Dynamical Instability ◽  
Central Temperature ◽  
Electron Positron ◽  
Instability Regions ◽  
Electron Positron Pair ◽  
Very High

The adiabatic effects of electron-positron pair-production on the dynamical instability of very-massive stars is investigated from stellar progenitors of carbon-oxygen cores within the range of 64 M < MCO < 133 M  both with and without rotation. At a very high temperature and relatively low density; the production of electron-positron pairs in the centres of massive stars leads the adiabatic index to below 4/3. The adiabatic quantities are evaluated by constructing a model into a thermodynamically consistent electron-positron equation of state (EoS) table. It is observed that the adiabatic indices in the instability regions of the rotating models are fundamentally positive with central temperature and density. Similarly, the mass of the oxygen core within the instability region has accelerated the adiabatic indices in order to compress the star, while the mass loss and adiabatic index in the non-rotating model exponentially decay. In the rotating models, a small amount of heat is required to increase the central temperature for the end fate of the massive stars. The dynamic of most of the adiabatic quantities show a similar pattern for all the rotating models. The non-rotating model may not be suitable for inducing the instability. Many adiabatic quantities have shown great effects on the dynamical instability of the massive stars due to electron-positron pair-production in their centres. The results of this work would be useful for better understanding of the end fate of very-massive stars.

R&D PROGRESS TOWARD FUTURE LINEAR COLLIDERS

2000 ◽  
Vol 15 (supp01b) ◽  
pp. 806-815
Author(s):  
GUSTAV-ADOLF VOSS
Keyword(s):  
Peak Power ◽  
Linear Collider ◽  
High Energy ◽  
High Peak Power ◽  
Rf Power ◽  
Electron Positron ◽  
Linear Colliders ◽  
Very High Energy ◽  
Very High ◽  
Low Emittance

During the last twenty years, there has been a world wide effort to develop the physics and technology of linear colliders. Present goals at SLAC, KEK, and DESY are to bring the R&D efforts to the point where proposals for 500/1000 GeV cms electron-positron colliders can be officially submitted in the years 2002/2003. The CLIC study at CERN aims at a second generation very high energy electron-positron collider, to be considered after completion of the LHC. The main areas of hardware R&D include efficient accelerating waveguides without harmful higher order mode (h.o.m.) effects, high peak power klystrons, klystron modulators, and rf-power compression. Test facilities have been put in place for the testing of h.o.m. behavior of new waveguide designs (ASSET), focusing of low emittance beams to spot sizes in the nanometer range (FFTB), and damping particle oscillations in a special damping ring (ATF) to prepare low emittance bunch trains of electrons for injection into linear colliders. The TESLA collaboration is making a major effort to develop the required technology for a superconducting linear collider. Test accelerator sections, which employ all the necessary new accelerator components, have been built and are currently being tested at SLAC and DESY.

R&D PROGRESS TOWARD FUTURE LINEAR COLLIDERS

1999 ◽  
Vol 14 (28) ◽  
pp. 1923-1931
Author(s):  
G.-A. VOSS
Keyword(s):  
Peak Power ◽  
Linear Collider ◽  
High Energy ◽  
High Peak Power ◽  
Rf Power ◽  
Electron Positron ◽  
Linear Colliders ◽  
Very High Energy ◽  
Very High ◽  
Low Emittance

During the last 20 years there has been a worldwide effort to develop the physics and technology of linear colliders. Present goals at SLAC, KEK and DESY are to bring the R&D efforts to the point where proposals for 500/1000 GeV cms electron–positron colliders can be officially submitted in the years 2002/2003. The CLIC study at CERN aims at a second generation very high energy electron–positron collider, to be considered after completion of the LHC. The main areas of hardware R&D include efficient accelerating waveguides without harmful higher order mode (h.o.m) effects, high peak power klystrons, klystron modulators and rf-power compression. Test facilities have been put in place for the testing of h.o.m behavior of new waveguide designs (ASSET), focusing on low emittance beams to spot sizes in the nanometer range (FFTB) and damping particle oscillations in a special damping ring (ATF) to prepare low emittance bunch trains of electrons for injection into linear colliders. The TESLA collaboration is making a major effort to develop the required technology for a superconducting linear collider. Test accelerator sections, which employ all the necessary new accelerator components, have been built and are currently being tested at SLAC and DESY.

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