Oscillatory Screening Effects on Elastic Collisions in Dense Electron-Ion Quantum Plasmas

2009 ◽  
Vol 64 (3-4) ◽  
pp. 237-241 ◽  
Author(s):  
Yo-Han Koo ◽  
Young-Dae Jung
Keyword(s):  
Phase Shift ◽  
Total Cross Section ◽  
Cross Section ◽  
Scattering Amplitude ◽  
Wave Number ◽  
Optical Theorem ◽  
Screening Effect ◽  
Quantum Plasmas ◽  
Quantum Wave ◽  
Scattering Phase

Abstract The oscillatory screening effects on elastic electron-ion collisions are investigated in dense quantum plasmas. The eikonal method with the modified Debye-Hückel potential is employed to obtain the scattering phase shift and scattering amplitude. In addition, the total elastic collision cross section is obtained by the optical theorem with the forward scattering amplitude in quantum plasmas. It is shown that the modified Debye-Hückel screening in quantum plasmas produces the oscillatory behaviour of the scattering phase shift. In addition, the minimum position of the phase shift is receded from the target ion with decreasing the quantum wave number. It is also found that the oscillatory screening effect suppresses the differential cross section. The total cross section is also found to be decreased due to the oscillatory screening effect. In addition, it is shown that the total cross section decreases with an increase of the quantum wave number

Influence of Electron Exchange and Quantum Shielding on the Elastic Collisions in Quantum Plasmas

2013 ◽  
Vol 68 (10-11) ◽  
pp. 686-692
Author(s):  
Gyeong Won Lee ◽  
Young-Dae Jung
Keyword(s):  
Phase Shift ◽  
Cross Section ◽  
Fermi Energy ◽  
Collision Energy ◽  
Collision Cross Section ◽  
Electron Exchange ◽  
Plasmon Energy ◽  
Exchange Effect ◽  
Quantum Plasmas ◽  
Scattering Phase

The influence of electron exchange and quantum shielding on the elastic electron-ion collision is investigated in degenerate quantum plasmas. The second-order eikonal method and effective screened potential are employed to obtain the scattering phase shift and collision cross section as functions of the impact parameter, collision energy, electron-exchange parameter, Fermi energy, and plasmon energy. It is found that the electron-exchange effect enhances the eikonal scattering phase shift as well as the eikonal collision cross section in quantum plasmas. The maximum position of the differential eikonal collision cross section is found to be receded from the collision center with an increase of the electron-exchange effect. It is interesting to note that the influence of the electron exchange on the eikonal collision cross section decreases with increasing collision energy. It is also found that the eikonal collision cross section decreases with an increase of the plasmon energy and, however, increases with increasing Fermi energy.

Diffractive results from CDF

2015 ◽  
Vol 30 (08) ◽  
pp. 1542003 ◽  
Author(s):  
Konstantin Goulianos
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Imaginary Part ◽  
Scattering Amplitude ◽  
Pomeron Exchange ◽  
Optical Theorem ◽  
Double Dissociation ◽  
Elastic Scattering Amplitude ◽  
Theoretical Predictions

We present a reference review of diffractive results from CDF for [Formula: see text] collisions at [Formula: see text], 630, 1800, and 1960 GeV at the Tevatron, published in 19 PRL/PRD papers from 1994 to 2012. Both soft and hard diffractive results are included for single and/or double dissociation, central diffraction or double Pomeron exchange (where both the proton and antiproton remain intact), multi-gap diffraction (a combination of single and double dissociation), elastic scattering, and the total cross-section, which through the optical theorem is related to the imaginary part of the forward elastic scattering amplitude. In each review, we include the comparisons made by CDF with theoretical predictions.

scholarly journals First determination of the $${\rho }$$ parameter at $${\sqrt{s} = 13}$$ TeV: probing the existence of a colourless C-odd three-gluon compound state

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
G. Antchev ◽  
P. Aspell ◽  
I. Atanassov ◽  
V. Avati ◽  
J. Baechler ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Total Cross Section ◽  
Cross Section ◽  
Scattering Amplitude ◽  
Theoretical Models ◽  
Proton Proton ◽  
Slowing Down ◽  
Proton Elastic Scattering ◽  
Compound State ◽  
Elastic Scattering Amplitude

Abstract The TOTEM experiment at the LHC has performed the first measurement at $$\sqrt{s} = 13\,\mathrm{TeV}$$s=13TeV of the $$\rho $$ρ parameter, the real to imaginary ratio of the nuclear elastic scattering amplitude at $$t=0$$t=0, obtaining the following results: $$\rho = 0.09 \pm 0.01$$ρ=0.09±0.01 and $$\rho = 0.10 \pm 0.01$$ρ=0.10±0.01, depending on different physics assumptions and mathematical modelling. The unprecedented precision of the $$\rho $$ρ measurement, combined with the TOTEM total cross-section measurements in an energy range larger than $$10\,\mathrm{TeV}$$10TeV (from 2.76 to $$13\,\mathrm{TeV}$$13TeV), has implied the exclusion of all the models classified and published by COMPETE. The $$\rho $$ρ results obtained by TOTEM are compatible with the predictions, from other theoretical models both in the Regge-like framework and in the QCD framework, of a crossing-odd colourless 3-gluon compound state exchange in the t-channel of the proton–proton elastic scattering. On the contrary, if shown that the crossing-odd 3-gluon compound state t-channel exchange is not of importance for the description of elastic scattering, the $$\rho $$ρ value determined by TOTEM would represent a first evidence of a slowing down of the total cross-section growth at higher energies. The very low-|t| reach allowed also to determine the absolute normalisation using the Coulomb amplitude for the first time at the LHC and obtain a new total proton–proton cross-section measurement $$\sigma _{\mathrm{tot}} = (110.3 \pm 3.5)\,\mathrm{mb}$$σtot=(110.3±3.5)mb, completely independent from the previous TOTEM determination. Combining the two TOTEM results yields $$\sigma _{\mathrm{tot}} = (110.5 \pm 2.4)\,\mathrm{mb}$$σtot=(110.5±2.4)mb.

Nonthermal effects on the elastic electron–atom collision in generalized Lorentzian semiclassical plasmas: Lorentzian renormalization shielding

2015 ◽  
Vol 81 (2) ◽  
Author(s):  
Woo-Pyo Hong ◽  
Young-Dae Jung
Keyword(s):  
Phase Shift ◽  
Cross Section ◽  
Collision Cross Section ◽  
Effective Interaction ◽  
Elastic Electron ◽  
Electron Atom ◽  
Energy Impact ◽  
Scattering Phase ◽  
Total Collision ◽  
Atom Collision

The Lorentzian renormalization plasma shielding effects on the elastic electron–atom collision are investigated in generalized Lorentzian semiclassical plasmas. The eikonal analysis and the effective interaction potential are employed to obtain the eikonal scattering phase shift, differential eikonal collision cross section, and total eikonal collision cross section as functions of the collision energy, impact parameter, nonthermal renormalization parameter, and spectral index of the Lorentzian plasma. It is found that the influence of Lorentzian renormalization shielding suppresses the eikonal scattering phase shift and, however, enhances the eikonal collision cross section in Lorentzian semiclassical plasmas. Additionally, the energy dependence on the total collision cross section in nonthermal plasmas is found to be more significant than that in thermal plasmas.

Eikonal-Glauber Thomas–Fermi model for atomic collisions with many-electron atoms for plasma applications

2018 ◽  
Vol 84 (3) ◽  
Author(s):  
Myoung-Jae Lee ◽  
Young-Dae Jung
Keyword(s):  
Form Factor ◽  
Phase Shift ◽  
Momentum Transfer ◽  
Cross Section ◽  
Atomic Charge ◽  
Fermi Model ◽  
Thomas Fermi ◽  
Scattering Phase ◽  
Effective Atomic Charge ◽  
Atomic Form Factor

We have derived the universal eikonal-Glauber Thomas–Fermi model for atomic collision cross-sections with many-electron atoms, such as iron and tungsten atoms, including the influence of atomic screening in fusion devices and plasma technologies. The eikonal-Glauber method is employed to obtain the analytic expressions for the effective atomic charge, the scattering phase shift and the atomic cross-section in terms of the atomic form factor and the Mott–Massey screening parameter. The result shows that the effective atomic charge would be the same as the case of the net nuclear charge for the large momentum transfer domain and becomes zero without momentum transfer due to the influence of bound atomic electrons. It is shown that the eikonal scattering phase shift and the total eikonal-Glauber scattering cross-section increase with increasing charge number$Z$of the nucleus of the target atom. It is also found that the charge dependence of the total eikonal-Glauber scattering cross-section decreases with an increase of the scaled collision energy since the atomic form factor is small for large collision energies.

Electromagnetic scattering by a perfectly conducting elliptic disk

1987 ◽  
Vol 65 (7) ◽  
pp. 723-734 ◽  
Author(s):  
Jonas Björkberg ◽  
Gerhard Kristensson
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Electromagnetic Scattering ◽  
Recurrence Relations ◽  
Scattering Amplitude ◽  
Azimuthal Angle ◽  
Low Frequency ◽  
Prolate Spheroid ◽  
Numerical Computations ◽  
Theoretical Results

Electromagnetic scattering from a perfectly conducting elliptic disk is treated by means of the null-field approach. The disk is obtained as the zero-thickness limit of an ellipsoid. It is shown that in this limit all relevant matrix elements have a well-defined limit. Owing to the lack of axial symmetry, an integral that can not be solved analytically remains in the azimuthal angle. In an appendix, an efficient algorithm to solve these integrals by means of recurrence relations is presented. The formalism is attractive for numerical computations, and stable results for very eccentric disks have been obtained. The first few terms in the low-frequency expansion of the total cross section are derived. Numerical computations of the scattering amplitude and the total cross section illustrate the theoretical results. In a final appendix, the thin wire limit of the elliptic disk is discussed, and a comparison with corresponding results of a prolate spheroid is presented.

Quantum Shielding Effects on the Eikonal Collision Cross Section in Strongly Coupled Two-temperature Plasmas

2017 ◽  
Vol 72 (5) ◽  
pp. 433-439
Author(s):  
Myoung-Jae Lee ◽  
Young-Dae Jung
Keyword(s):  
Phase Shift ◽  
Cross Section ◽  
Strongly Coupled ◽  
Scattering Phase ◽  
Impact Parameters ◽  
De Broglie Wavelength ◽  
Ion Collision ◽  
The Impact ◽  
Two Temperature ◽  
Shielding Effects

AbstractThe influence of nonisothermal and quantum shielding on the electron-ion collision process is investigated in strongly coupled two-temperature plasmas. The eikonal method is employed to obtain the eikonal scattering phase shift and eikonal cross section as functions of the impact parameter, collision energy, electron temperature, ion temperature, Debye length, and de Broglie wavelength. The results show that the quantum effect suppresses the eikonal scattering phase shift for the electron-ion collision in two-temperature dense plasmas. It is also found that the differential eikonal cross section decreases for small impact parameters. However, it increases for large impact parameters with increasing de Broglie wavelength. It is also found that the maximum position of the differential eikonal cross section is receded from the collision center with an increase in the nonisothermal character of the plasma. In addition, it is found that the total eikonal cross sections in isothermal plasmas are always greater than those in two-temperature plasmas. The variations of the eikonal cross section due to the two-temperature and quantum shielding effects are also discussed.

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