Pion and muon production in<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>−</mml:mo></mml:msup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>e</mml:mi><mml:mo>+</mml:mo></mml:msup></mml:math>,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>γ</mml:mi></mml:math>plasma

Kuznetsova, Inga; Habs, D.; Rafelski, Johann

doi:10.1103/physrevd.78.014027

Cited by 45 publications

(61 citation statements)

References 17 publications

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“…Apparently at initial temperature, it appears to be completely opaque as discussed in Refs. [5,11]. However, it may not be so forever as we will see below.…”

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confidence: 96%

Gamma flashes from relativistic electron-positron plasma droplets

Mustafa

Kämpfer

2009

Phys. Rev. A

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Ultra-intense lasers are expected to produce, in near future, relativistic electron-positron plasma droplets. Considering the local photon production rate in complete leading order in quantum electrodynamics (QED), we point out that these droplets are interesting sources of gamma ray flashes. . Electron-positron plasmas are also interesting for astrophysical scenario [10]. Temperatures of about T ∼ 10 MeV, in a laser-generated plasma, would open, furthermore, channels for muon or pion production [11]. While these channels are interesting for their own right (see [12] for another avenue for laser driven particle production), a hot e + e − γ plasma droplet, exploding after the creation process by the enormous thermodynamic pressure, is a source of γ radiation. Such short γ flashes may be of future use in ultra-fast spectroscopic investigations of various kind.In this note, we are going to present estimates of the photon spectrum emerging from a e + e − γ plasma droplet with temperatures in the 10 MeV range. In contrast to often employed particle-in-cell (PIC) simulations (see [3] for a study of the start-up phase of a similarly hot plasma), we base our considerations on results from QED thermo-field theory. The expansion dynamics is treated in a schematic way, as our emphasis is on the photon emission characteristics.The calculation of the local spontaneous photon emission rate from a QED (electron-positron) plasma has been outlined in [13] to complete leading order in elec- * Electronic address: musnhigolam.mustafa@saha.ac.in † Electronic address: b.kaempfer@fzd.de tromagnetic coupling α by including two-loop order. The result, at the heart of our note, may be presented aswhere n F (E γ ) = (exp(E γ /T ) + 1) −1 denotes the Fermi distribution, and the dynamically generated asymptotic mass squared of the electron is m 2 ∞ = 2m 2 th . The thermal mass squared is given by m 2 th = e 2 T 2 /8 with e 2 = 4πα (The considerations apply for T > m e ± which are different from the non-relativistic case where the relevant scales are given by the masses of plasma particles and the temperature [5].) E γ = u · k is a short hand notation for the Lorentz scalar product of the medium's four-velocity u(t, x) and the photon's four-momentum k. This rate includes 2 ↔ 2 processes from one loop [14], viz., Compton scattering and pair annihilation which generate the leading logarithmic contribution (first three terms in (1)). In addition, the rate also includes the inelastic processes [15] from two-loop like bremsstrahlung (fourth term) and offshell pair annihilation (fifth term) with the correct incorporation [13,16] of the Landau-Pomeranchuk-Migdal effect that limits the coherence length of the emitted radiation. A common feature of the latter two processes is that they have off-shell fermion next to the vertex where the photon is emitted, and the virtuality of the fermion becomes very small if the photon is emitted in forward direction. However, contrary to the one-loop diagrams, the singularity is linear instead of logarithmic, and ...

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“…Apparently at initial temperature, it appears to be completely opaque as discussed in Refs. [5,11]. However, it may not be so forever as we will see below.…”

mentioning

confidence: 96%

Gamma flashes from relativistic electron-positron plasma droplets

Mustafa

Kämpfer

2009

Phys. Rev. A

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“…These effects are independent since they operate in ortogonal directions of the phase space, so one can estimate the value of external electric field at which phase space blocking occurs by comparing their rates. Such analysis gives us the following inequality In this figure are shown, for all the cases under interest, the half period of the first oscillation t 1 (triangles), the characteristic time-scales t a (squares) needed to the pairs oscillation frequency to reach the plasma frequency and the time t γ (circles) which satisfies the condition τ (t γ ) ≃ 1 for the optical depth defined in (26) . The value of t a for the case E 0 = 2E c is shown in fig.…”

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confidence: 99%

On the frequency of oscillations in the pair plasma generated by a strong electric field

et al. 2011

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We study the frequency of the plasma oscillations of electron-positron pairs created by the vacuum polarization in an uniform electric field with strength E in the range 0.2 E c < E < 10 E c . Following the approach adopted in [1] we work out one second order ordinary differential equation for a variable related to the velocity from which we can recover the classical plasma oscillation equation when E → 0. Thereby, we focus our attention on its evolution in time studying how this oscillation frequency approaches the plasma frequency. The time-scale needed to approach to the plasma frequency and the power spectrum of these oscillations are computed. The characteristic frequency of the power spectrum is determined uniquely from the initial value of the electric field strength. The effects of plasma degeneracy and pair annihilation are discussed. It has been shown that, due to back reaction and screening effects of e + e − pairs on external electric fields, positrons and electrons move back and forth coherently with alternating electric field: the so called plasma oscillations. In [1] it was pointed out that this phenomenon occurs also when E ≤ E c giving emphasis on the fact that, for overcritical (undercritical) field, a large (small) fraction of the initial electromagnetic energy is converted into the rest mass of pairs, whereas a small (large) fraction is converted Email addresses: Alberto.Benedetti@icra.it (A. Benedetti), wenbiao@icra.it (W.-B. Han), ruffini@icra.it (R. Ruffini), veresh@icra.it (G.V. Vereshchagin) into kinetic energy. In [17] the case of spatially inhomogeneous electric field has been considered, the emitted radiation spectrum far from the oscillation region was obtained, presenting a narrow feature.In this Letter we return to basic equations describing pair creation and plasma oscillations in uniform unbound electric field. We first derive a master equation for a new variable constructed from hydrodynamic velocity, which turns out to be second order ordinary differential equation. This equation is reduced to the classic plasma oscillations equation describing Langmuir waves in the limit of small electric field. The frequency of oscillations is then shown to be almost equal to the plasma frequency, which is strongly time dependent in the case under consideration. Finally, the spectrum of bremsstrahlung radiation is computed following [17] and its characteristic feature is identified as a function of initial value of the electric field strength.As in [1] we apply an approach based on continuity, energy-momentum conservation and Maxwell equations in order to account for the back reaction of the created pairs focusing on the range 0.2 E c < E < 10 E c .We assume that electrons and positrons are created at rest in pairs, due to vacuum polarization in uniform electric field [3]- [5], [18]-[20] with the average rate 1 per 1 We use in the following the system of units where = c = 1, e = √ α ≈ 1/137, α being the fine structure constant.

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“…It is an interesting plasma on its own and has been studied in reference [36]. Via photon pairs or e + e − pairs pions may be produced, a process studied in reference [37]. In both references the hot e + e − γ plasma was assumed to be produced by two circular polarized laser beams, which compress and accelerate electrons in a gold foil that much, that the electrons produce positrons in the field of the high Z nucleus [38].…”

Section: Cold Pion and Kaon Condensatesmentioning

confidence: 99%

“…On the other hand we now focus not 10 keV photons but 10 MeV photons with a 10 3 -fold reduction in wavelength, thus increasing the density by up to 10 9 and the critical temperature by 10 6 . The hot e + e − γ plasma is of interest by itself [36] and the production of hadrons by the interaction of photon pairs or electron positron pairs can be studied [37]. Here new collective modes of ultrarelativistic e + e − plasmas like the fermionic plasmino mode have been predicted [36].…”

Section: Cold Pion and Kaon Condensatesmentioning

confidence: 99%

Vision of a fully laser-driven ${\sf n\gamma}{-}{\sf m\gamma}$ collider

et al. 2009

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Abstract. The use is suggested of a laser-accelerated dense electron sheet with an energy of (E =γmc 2 ) as a relativistic mirror to reflect coherently a second laser with photon energy ω, generating by the Doppler boost high-energy γ photons with ω = 4γ2 ω and short duration [A. Einstein, Annalen der Physik 17, 891 (1905); D. Habs et al., Appl. Phys. B 93, 349 (2008)]. Two of these counter-propagating γ beams are focused by the parabolically shaped electron sheets into the interaction region with small, close to diffraction-limited, spot size. Comparing the new nγ−mγ collider with former proposed γγ collider schemes we achieve the conversion of many photon-pairs in a small space-time volume to matter-antimatter particles, while in the other discussed setups only two isolated, much more high-energetic photons will be converted, reaching in the new approach much higher energy densities and temperatures. With a γ-field strength somewhat below the Schwinger limit we can reach this complete conversion of the γ bunch energy into e + e − or quark-antiquark qq-plasmas. , 2006)] the strong induced transition into this coherent state is of special interest for single-cycle γ pulses. Due to annihilation these cold coherent states are very short-lived. For γ beams with photon energies of 1-10 keV the rather cold e + e − -plasma or e + e − -BEC expands to a cold dense aggregate of positronium (Ps) atoms, where the production of Ps molecules is discussed. For photon energies of 1-10 MeV we discuss the production of a cold induced π 0 -BEC followed by the formation of molecules. For the direct population of higher qq densities we can study condensates of color-neutral mesons with enhanced population. For a γγ collider with several-cycle laser pulses the following cycles heat up the fermion-antifermion ff system to a certain temperature. Thus we can reach high energy densities and temperatures of an e + e − γ plasma, where the production of hadrons in general or the quark-gluon phase transition can be observed. Within the long-term goal of very high photon energies of about 1 GeV in the nγ−mγ-collider, even the electro-weak phase transition or SUSY phase transition could be reached.PACS. 42.55.Vc X-and gamma-ray lasers -29.27.-a Beams in particle accelerators -41.75.Jv Laser-driven acceleration -41.75.Ht Relativistic electron and positron beams

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Pion and muon production ine−,e+,γplasma

Cited by 45 publications

References 17 publications

Gamma flashes from relativistic electron-positron plasma droplets

Gamma flashes from relativistic electron-positron plasma droplets

On the frequency of oscillations in the pair plasma generated by a strong electric field

Vision of a fully laser-driven ${\sf n\gamma}{-}{\sf m\gamma}$ collider

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