scholarly journals Equilibration of the chiral asymmetry due to finite electron mass in electron-positron plasma

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
A. Boyarsky ◽  
V. Cheianov ◽  
O. Ruchayskiy ◽  
O. Sobol
Keyword(s):  
Electron Mass ◽  
Chiral Asymmetry ◽  
Electron Positron

scholarly journals Effects of Positron Density and Temperature on Large Amplitude Ion-acoustic Waves in an Electron - Positron - Ion Plasma

1997 ◽  
Vol 50 (2) ◽  
pp. 309 ◽  
Author(s):  
Y. N. Nejoh
Keyword(s):  
Acoustic Waves ◽  
Large Amplitude ◽  
Density Ratio ◽  
Present Theory ◽  
Electron Mass ◽  
Mass Ratio ◽  
Ion Acoustic Waves ◽  
Ion Plasma ◽  
Electron Positron ◽  
Ion Acoustic

The nonlinear wave structures of large amplitude ion-acoustic waves are studied in a plasma with positrons. We have presented the region of existence of the ion-acoustic waves by analysing the structure of the pseudopotential. The region of existence sensitively depends on the positron to electron density ratio, the ion to electron mass ratio and the positron to electron temperature ratio. It is shown that the maximum Mach number increases as the positron temperature increases and the region of existence of the ion-acoustic waves spreads as the positron temperature increases. The present theory is applicable to analyse large amplitude ion-acoustic waves associated with positrons which may occur in space plasmas.

scholarly journals Magnetic energy dissipation and origin of non-thermal spectra in radiatively efficient relativistic sources

2019 ◽  
Vol 491 (3) ◽  
pp. 3900-3907 ◽  
Author(s):  
E Sobacchi ◽  
Y E Lyubarsky
Keyword(s):  
Energy Distribution ◽  
Magnetic Energy ◽  
Strong Electric Field ◽  
Spectral Energy Distribution ◽  
Lorentz Factor ◽  
High Energy ◽  
Local Magnetic Field ◽  
Spectral Energy ◽  
Electron Mass ◽  
Electron Positron

ABSTRACT The dissipation of turbulent magnetic fields is an appealing scenario to explain the origin of non-thermal particles in high-energy astrophysical sources. However, it has been suggested that the particle distribution may effectively thermalize when the radiative (synchrotron and/or Inverse Compton) losses are severe. Inspired by recent particle-in-cell simulations of relativistic turbulence, which show that electrons are impulsively heated in intermittent current sheets by a strong electric field aligned with the local magnetic field, we instead argue that in plasmas where the particle number density is dominated by the pairs (electron–positron and electron–positron–ion plasmas): (i) as an effect of fast cooling and of different injection times, the electron energy distribution is dne/dγ ∝ γ−2 for γ ≲ γheat (the Lorentz factor γheat being close to the equipartition value), while the distribution steepens at higher energies; (ii) since the time-scales for the turbulent fields to decay and for the photons to escape are of the same order, the magnetic and the radiation energy densities in the dissipation region are comparable; (iii) if the mass energy of the plasma is dominated by the ion component, the pairs with a Lorentz factor smaller than a critical one (of the order of the proton-to-electron mass ratio) become isotropic, while the pitch angle remains small otherwise. The outlined scenario is consistent with the typical conditions required to reproduce the spectral energy distribution of blazars, and allows one to estimate the magnetization of the emission site. Finally, we show that turbulence within the Crab Nebula may power the observed gamma-ray flares if the pulsar wind is nearly charge separated at high latitudes.

scholarly journals Electron–positron pair plasma in TXS 0506+056 and the ‘neutrino flare’ in 2014–2015

2020 ◽  
Vol 497 (4) ◽  
pp. 5318-5325
Author(s):  
N Fraija ◽  
E Aguilar-Ruiz ◽  
A Galván-Gámez
Keyword(s):  
Gamma Ray ◽  
Neutrino Flux ◽  
High Energy ◽  
Electron Mass ◽  
Pair Plasma ◽  
Electron Positron ◽  
Accelerated Protons ◽  
Temporal And Spatial ◽  
Electron Positron Pair ◽  
Simultaneous Activity

ABSTRACT The detection of a prolonged flaring activity from blazar TXS 0506+056 in temporal and spatial coincidence with the energetic neutrino IceCube-170922A provided evidence about the photohadronic interactions in this source. However, analysis of the archival neutrino and multiwavelength data from the direction of this blazar between 2014 September and 2015 March revealed a ‘neutrino flare’ without observing quasi-simultaneous activity in the gamma-ray bands, posing challenges to established models. Electron–positron (e±) pairs generated from the accretion discs have been amply proposed as a mechanism of bulk acceleration of sub-relativistic and relativistic jets. These pairs annihilate inside the source producing a line around the electron mass, which is blueshifted in the observed frame (on Earth) and redshifted in the frame of the dissipation region of the jet. The redshifted photons in the dissipation region interact with accelerated protons, producing high-energy neutrinos that contribute significantly to the diffuse neutrino flux in the ∼10–20 TeV energy range in connection with gamma-rays from the photopion process, which can be detected by future MeV orbiting satellites. Based on this phenomenological model, we can explain the ‘neutrino flare’ reported in 2014–1015.

scholarly journals MAGNETIC FIELDS IN QUANTUM DEGENERATE SYSTEMS AND IN VACUUM

2007 ◽  
Vol 16 (02n03) ◽  
pp. 165-173 ◽  
Author(s):  
H. PÉREZ ROJAS ◽  
E. RODRÍGUEZ QUERTS
Keyword(s):  
Magnetic Moment ◽  
W Bosons ◽  
Einstein Condensate ◽  
Electron Mass ◽  
State Behavior ◽  
Bose Einstein Condensate ◽  
Electron Positron ◽  
Vector Bosons ◽  
Neutral Vector ◽  
Bose Einstein

We consider self-magnetization of charged and neutral vector bosons bearing a magnetic moment in a gas and in vacuum. For charged vector bosons (W bosons) a divergence of the magnetization in both the medium and the electroweak vacuum occurs for the critical field [Formula: see text]. For B > Bwc the system is unstable. This behavior suggests the occurrence of a phase transition at B = Bc, where the field is self-consistently maintained. This mechanism actually prevents B from reaching the critical value Bc. For virtual neutral vector bosons bearing an anomalous magnetic moment, the ground state behavior for [Formula: see text] have a similar behavior. The magnetization in the medium is associated to a Bose–Einstein condensate and we conjecture a similar condensate occurs also in the case of vacuum. The model is applied to virtual electron-positron pairs bosonization in a magnetic field [Formula: see text], where me is the electron mass. This would lead also to vacuum self-magnetization in QED, where in both cases the symmetry breaking is due to a condensate of quasi-massless particles.

Search for Excited and Exotic Electrons at the Collider Detector at Fermilab

2005 ◽  
Vol 20 (15) ◽  
pp. 3290-3293
Author(s):  
◽  
HEATHER KAY GERBERICH
Keyword(s):  
Transverse Momentum ◽  
Contact Interaction ◽  
Hadron Collider ◽  
Interaction Model ◽  
Energy Scale ◽  
Excited Electron ◽  
Electron Mass ◽  
High Transverse Momentum ◽  
Final State ◽  
Electron Positron

The first search at a hadron collider for the production of excited and exotic electrons in association with a positron is presented. The excited electron decays to an electron and a photon with high transverse momentum yielding an electron+positron+photon final state signature. The search uses 202 pb-1 of data collected in [Formula: see text] collisions at [Formula: see text] with the CDF II detector during 2001-2003. No excess of dielectron+photon events is observed. We present the e* sensitivity in the parameter space of the excited electron mass and the compositeness energy scale for both a gauge mediated and contact interaction model.

scholarly journals Scaling behavior of circular colliders dominated by synchrotron radiation

2015 ◽  
Vol 30 (23) ◽  
pp. 1544003 ◽  
Author(s):  
Richard Talman
Keyword(s):  
Synchrotron Radiation ◽  
Superconducting Magnets ◽  
Scaling Law ◽  
Simultaneous Optimization ◽  
Electron Mass ◽  
Lattice Matching ◽  
Optimization Task ◽  
Proton Mass ◽  
Electron Positron ◽  
Abstract Approach

The scaling formulas in this paper — many of which involve approximation — apply primarily to electron colliders like CEPC or FCC-ee. The more abstract “radiation dominated” phrase in the title is intended to encourage use of the formulas — though admittedly less precisely — to proton colliders like SPPC, for which synchrotron radiation begins to dominate the design in spite of the large proton mass. Optimizing a facility having an electron–positron Higgs factory, followed decades later by a p, p collider in the same tunnel, is a formidable task. The CEPC design study constitutes an initial “constrained parameter” collider design. Here the constrained parameters include tunnel circumference, cell lengths, phase advance per cell, etc. This approach is valuable, if the constrained parameters are self-consistent and close to optimal. Jumping directly to detailed design makes it possible to develop reliable, objective cost estimates on a rapid time scale. A scaling law formulation is intended to contribute to a “ground-up” stage in the design of future circular colliders. In this more abstract approach, scaling formulas can be used to investigate ways in which the design can be better optimized. Equally important, by solving the lattice matching equations in closed form, as contrasted with running computer programs such as MAD, one can obtain better intuition concerning the fundamental parametric dependencies. The ground-up approach is made especially appropriate by the seemingly impossible task of simultaneous optimization of tunnel circumference for both electrons and protons. The fact that both colliders will be radiation dominated actually simplifies the simultaneous optimization task. All GeV scale electron accelerators are “synchrotron radiation dominated”, meaning that all beam distributions evolve within a fraction of a second to an equilibrium state in which “heating” due to radiation fluctuations is canceled by the “cooling” in RF cavities that restore the lost energy. To the contrary, until now, the large proton to electron mass ratio has caused synchrotron radiation to be negligible in proton accelerators. The LHC beam energy has still been low enough that synchrotron radiation has little effect on beam dynamics; but the thermodynamic penalty in cooling the superconducting magnets has still made it essential for the radiated power not to be dissipated at liquid helium temperatures. Achieving this has been a significant challenge. For the next generation p, p collider this will be even more true. Furthermore, the radiation will effect beam distributions on time scales measured in minutes, for example causing the beams to be flattened, wider than they are high. In this regime scaling relations previously valid only for electrons will be applicable also to protons.

scholarly journals Slab magnetised non-relativistic low-beta electron–positron plasmas: collisionless heating, linear waves and reconnecting instabilities

2017 ◽  
Vol 83 (6) ◽  
Author(s):  
Alessandro Zocco
Keyword(s):  
Scale Effects ◽  
Kinetic Equations ◽  
Alfven Wave ◽  
Larmor Radius ◽  
Displacement Current ◽  
Electron Mass ◽  
Slab Geometry ◽  
Tearing Modes ◽  
First Order ◽  
Electron Positron

The properties of a non-relativistic magnetised low-beta electron–positron plasma in slab geometry are investigated. The two species are taken to be drift kinetic while we retain Larmor radius effects in quasi-neutrality, and inertia in Ohm’s law. A linear analysis shows that, for small magnetic perturbations, Alfvénic perturbations travel at the electron Alfvén speed, which is based on the electron mass. We discuss the role of the displacement current when Larmor-scale and Debye-scale effects are both retained. We predict the existence of a kinetic electron Alfvén wave which connects to the K-modes of Mishchenko et al. (J. Plasma Phys., 2017 (submitted)) in the electrostatic limit. It is found that linear drift waves are not supported by the system if the two species have the same temperature. Tearing modes can be driven unstable by equilibrium current density gradients. Also in this case, the characteristic time is based on the electron Alfvén speed. Nonlinear hybrid fluid-kinetic equations are also derived. It is shown that each species is described, to leading order, by the kinetic reduced electron heating model (KREHM) kinetic equation of Zocco & Schekochihin (Phys. Plasmas, vol. 18, 2011, 102309). The model is extended to retain first-order Larmor radius effects. It supports collisionless dispersive waves, which can greatly impact nonlinear magnetic reconnection. Diamagnetic effects enter the nonlinear equations via the first-order magnetic compressibility. A minimal nonlinear model for two-dimensional low-frequency isothermal pair plasmas is derived.

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