Wave production in an ultrarelativistic electron-positron plasma

1978 ◽  
Vol 219 ◽  
pp. 274 ◽  
Author(s):  
P. E. Hardee ◽  
W. K. Rose
Keyword(s):  
Ultrarelativistic Electron ◽  
Electron Positron

scholarly journals Resonant Production of an Ultrarelativistic Electron–Positron Pair at the Gamma Quantum Scattering by a Field of the X-ray Pulsar

Universe ◽  
2020 ◽  
Vol 6 (10) ◽  
pp. 164
Author(s):  
Vadim A. Yelatontsev ◽  
Sergei P. Roshchupkin ◽  
Viktor V. Dubov
Keyword(s):  
Gamma Quantum ◽  
Threshold Energy ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Quantum Scattering ◽  
X Ray ◽  
Ultrarelativistic Electron ◽  
Electron Positron ◽  
Resonant Production ◽  
Electron Positron Pair

The process of a resonant production of an ultrarelativistic electron–positron pair in the process of gamma-quantum scattering in the X-ray field of a pulsar is theoretically studied. This process has two reaction channels. Under resonant conditions, an intermediate electron (for a channel A) or a positron (for a channel B) enters the mass shell. As a result, the initial second-order process of the fine-structure constant in the X-ray field effectively splits into two first-order processes: the X-ray field-stimulated Breit–Wheeler process and the the X-ray field-stimulated Compton effect on an intermediate electron or a positron. The resonant kinematics of the process is studied in detail. It is shown that for the initial gamma quantum there is a threshold energy, which for the X-ray photon energy (1–102) keV has the order of magnitude (103–10) MeV. In this case, all the final particles (electron, positron, and final gamma quantum) fly in a narrow cone along the direction of the initial gamma quantum momentum. It is important to note that the energies of the electron–positron pair and the final gamma quantum depend significantly on their outgoing angles. The obtained resonant probability significantly exceeds the non-resonant one. The obtained results can be used to explain the spectrum of positrons near pulsars.

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 NEUTRINO SPIN RELAXATION IN MEDIUM WITH STOCHASTIC CHARACTERISTICS

2006 ◽  
Vol 21 (11) ◽  
pp. 2403-2413 ◽  
Author(s):  
MAXIM DVORNIKOV
Keyword(s):  
Spin Relaxation ◽  
Neutrino Interaction ◽  
Left Handed ◽  
Upper Limit ◽  
Ultrarelativistic Electron ◽  
Electron Positron ◽  
Primordial Plasma ◽  
Stochastic Characteristics ◽  
The Universe ◽  
Universe Evolution

The helicity evolution of a neutrino propagating in randomly moving and polarized matter is studied. The type of the neutrino interaction with background fermions is arbitrary. We derive the equation for the description of the averaged neutrino helicity evolution. In the particular case of a τ-neutrino interacting with ultrarelativistic electron–positron plasma, we obtain the expression for the neutrino helicity relaxation rate in the explicit form. We study the neutrino spin relaxation in the relativistic primordial plasma. Supposing that the conversion of left-handed neutrinos into right-handed ones is suppressed at the early stages of the Universe evolution, we get the upper limit on the τ-neutrino mass.

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