Dynamically Screened Elastic Collisions in Nonideal Plasmas

2006 ◽  
Vol 61 (7-8) ◽  
pp. 330-334
Author(s):  
Dong-Man Chang ◽  
Won-Seok Chang ◽  
Young-Dae Jung
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
Thermal Energy ◽  
Collision Energy ◽  
Debye Length ◽  
Parameter Analysis ◽  
Ion Collisions ◽  
Dynamic Screening ◽  
Nonideal Plasmas ◽  
The Impact

The dynamic screening effects on elastic electron-ion collisions are investigated in nonideal plasmas. The second-order eikonal method with the impact parameter analysis is employed to obtain the eikonal phase as a function of the impact parameter, collision energy, thermal energy, and Debye length. The result shows that the eikonal phase decreases with increasing the thermal energy. It is also found that the dynamic screening effects on the eikonal phase are more significant for large impact parameters. The total eikonal cross section is also found to be decreased with increasing the thermal energy. It is important to note that the eikonal cross section and the eikonal phase including the dynamic screening effects are found to be greater than those including the static screening effects.

Dynamic Screening Effects on Collisional Orientation Phenomena in Nonideal Plasmas

2007 ◽  
Vol 62 (12) ◽  
pp. 698-702
Author(s):  
Hwa-Min Kim ◽  
Young-Dae Jung
Keyword(s):  
Impact Parameter ◽  
Thermal Energy ◽  
Debye Length ◽  
Projectile Energy ◽  
Orientation Parameter ◽  
Screening Effect ◽  
Semiclassical Method ◽  
Dynamic Screening ◽  
Nonideal Plasmas ◽  
The Impact

Dynamic screening effects on orientation phenomena of 1s→2p±1 excitations in nonideal plasmas are investigated. A semiclassical method is employed to describe the motion of the projectile electron in order to investigate the variation of the orientation parameter as a function of the impact parameter, projectile energy, thermal energy, and Debye length. The result shows that the preference for the 1s→2p−1 transition significantly decreases with increasing projectile energy. It is found that the dynamic screening effect increases with increasing impact parameter and also with increasing projectile energy. It is also found that the 1s → 2p−1 preference decreases with increasing thermal energy.

Influence of the Dynamic Quantum Shielding on the Transition Bremsstrahlung Spectrum and the Gaunt Factor in Strongly Coupled Semiclassical Plasmas

2013 ◽  
Vol 68 (1-2) ◽  
pp. 165-171 ◽  
Author(s):  
Young-Dae Jung ◽  
Woo-Pyo Hong
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
Thermal Energy ◽  
Parameter Analysis ◽  
Projectile Energy ◽  
Bremsstrahlung Spectrum ◽  
Bremsstrahlung Radiation ◽  
Screening Effect ◽  
Strongly Coupled ◽  
Dynamic Screening

The influence of the dynamic quantum shielding on the transition bremsstrahlung spectrum is investigated in strongly coupled semiclassical plasmas. The effective pseudopotential and the impact parameter analysis are employed to obtain the bremsstrahlung radiation cross section as a function of the de Broglie wavelength, Debye length, impact parameter, radiation photon energy, projectile energy, and thermal energy. The result shows that the dynamic screening effect enhances the transition bremsstrahlung radiation cross section. It is found that the maximum position of the transition bremsstrahlung process approaches to the center of the shielding cloud with increasing thermal energy. It is also found that the dynamic screening effect on the bremsstrahlung radiation cross section decreases with an increase of the quantum character of the semiclassical plasma. In addition, it is found that the peak radiation energy increases with an increase of the thermal energy. It is also found that the dynamic quantum screening effect enhances the bremsstrahlung Gaunt factor, especially for the soft-photon case.

Collective Effects on the Transition Bremsstrahlung Spectrum due to the Polarization Interaction in Nonideal Plasmas

2009 ◽  
Vol 64 (1-2) ◽  
pp. 49-53
Author(s):  
Hwa-Min Kim ◽  
Young-Dae Jung
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
Photon Energy ◽  
Parameter Analysis ◽  
Collective Effects ◽  
Bremsstrahlung Spectrum ◽  
Collective Effect ◽  
Bremsstrahlung Radiation ◽  
Polarization Interaction ◽  
Nonideal Plasmas

The collective effects on the transition bremsstrahlung spectrum due to the polarization interaction between the electron and Debye shielding cloud of an ion are investigated in nonideal plasmas. The impact parameter analysis with the effective pseudopotential model taking into account the nonideal collective and plasma screening effects is applied to obtain the bremsstrahlung radiation cross-section as a function of the nonideality plasma parameter, Debye length, photon energy, and projectile energy. It is shown that the collective effects enhance the bremsstrahlung radiation cross-section and decrease with increasing impact parameter. It is also shown that the collective effect is the most significant near the maximum position of the bremsstrahlung cross-section. In addition, it is shown that the collective effect decreases with an increase of the radiation photon energy

scholarly journals The cos 2ϕ azimuthal asymmetry in ρ0 meson production in ultraperipheral heavy ion collisions

2020 ◽  
Vol 2020 (10) ◽  
Author(s):  
Hongxi Xing ◽  
Cheng Zhang ◽  
Jian Zhou ◽  
Ya-Jin Zhou
Keyword(s):  
Transverse Momentum ◽  
Vector Meson ◽  
Cross Section ◽  
Impact Parameter ◽  
Heavy Ion Collisions ◽  
Decay Product ◽  
Heavy Ion ◽  
Azimuthal Asymmetry ◽  
Ion Collisions ◽  
The Impact

Abstract We present a detailed study of vector meson photoproduction in ultraperipheral heavy ion collisions (UPCs). Using the dipole model, we develop a framework for the joint impact parameter and transverse momentum dependent cross sections. We compute the unpolarized cross section and cos 2ϕ azimuthal angular correlation for ρ0 photoproduction with ϕ defined as the angle between the ρ0’s transverse momentum and its decay product pion meson’s transverse momentum. Our result on unpolarized coherent differential cross section gives excellent description to the STAR experimental data. A first compari- son between theoretical calculation and experimental measurement on the cos 2ϕ azimuthal asymmetry, which results from the linearly polarized photons, is performed and reasonable agreement is reached. We find out the characteristic diffractive patterns at both RHIC and LHC energies and predict the impact parameter dependent cos 2ϕ azimuthal asymmetries for ρ0 photoproduction by considering UPCs and peripheral collisions. The future experimental measurements at RHIC and LHC relevant to our calculations will provide a tool to rigorously investigate the coherent and incoherent production of vector meson in UPCs, as well as to probe the nuclear structure in heavy ion collisions.

Influence of the Dynamic Shielding on the Collisional Entanglement Fidelity in Strongly Coupled Semiclassical Plasmas

2013 ◽  
Vol 68 (1-2) ◽  
pp. 152-156 ◽  
Author(s):  
Dae-Han Ki ◽  
Young-Dae Jung
Keyword(s):  
Thermal Energy ◽  
Collision Energy ◽  
Debye Length ◽  
Plasma Temperature ◽  
Partial Wave Analysis ◽  
Wave Analysis ◽  
Strongly Coupled ◽  
Dynamic Screening ◽  
Effective Dynamic ◽  
De Broglie Wavelength

The influence of the dynamic plasma shielding on the collisional entanglement fidelity is investigated in strongly coupled semiclassical plasmas. The partial wave analysis with the effective dynamic screening length is employed to obtain the dynamic entanglement fidelity as a function of collision energy, de Broglie wavelength, Debye length, and thermal energy. The results show that the collisional entanglement fidelity increases with increasing plasma temperature as well as de Broglie wavelength and, however, decreases with an increase of the Debye length. It is also found that the dynamic screening effect suppresses the collisional entanglement fidelity in strongly coupled semiclassical plasmas. In addition, it is found that the entanglement fidelity decreases with increasing de Broglie wavelength and, however, increases with increasing thermal energy. It is also found that the thermal effect on the entanglement fidelity would be more significant in the domain of low-collision energies.

Nonthermal and Plasmon Effects on Elastic Electron-Ion Collisions in Hot Quantum Lorentzian Plasmas

2009 ◽  
Vol 64 (1-2) ◽  
pp. 44-48
Author(s):  
Hwa-Min Kima ◽  
Young-Dae Jung
Keyword(s):  
Cross Section ◽  
Collision Energy ◽  
Collision Cross Section ◽  
Plasma Temperature ◽  
Interaction Model ◽  
Elastic Electron ◽  
Plasma Parameters ◽  
Ion Collisions ◽  
Ion Collision ◽  
The Impact

The nonthermal and plasmon effects on elastic electron-ion collisions are investigated in hot quantum Lorentzian plasmas. The modified interaction model taking into account the nonthermal screening and plasmon effects is employed to represent the electron-ion interaction potential in hot quantum Lorentzian plasmas. The eikonal phase and differential collision cross-section are obtained as functions of the impact parameter, collision energy, spectral index, and plasma parameters by using the second-order eikonal analysis. It is shown that the plasmon effect suppresses the eikonal phase and collision cross-section for 0 < β (ћω0/kBT < 0.6) and, however, enhances it for 0.6 < β < 1, where ω0 is the plasma frequency and T is the plasma temperature. It is also shown that the nonthermal character of the quantum Lorentzian plasma suppresses the elastic electron-ion collision cross-section.

scholarly journals Orientation phenomena for electron–ion collisional excitations in a classical nonideal plasma

2002 ◽  
Vol 67 (2-3) ◽  
pp. 183-190
Author(s):  
YOUNG-DAE JUNG
Keyword(s):  
Impact Parameter ◽  
Interaction Potential ◽  
Plasma Parameter ◽  
Debye Length ◽  
Collective Effects ◽  
Projectile Energy ◽  
Nonideal Plasma ◽  
Orientation Parameter ◽  
Ion Collisions ◽  
The Impact

Orientation phenomena for direct 1s → 2p±1 excitations in electron–hydrogenic-ion collisions are investigated in a classical nonideal plasma. An effective pseudopotential model taking into account plasma-screening and collective effects is applied to describe the interaction potential in a nonideal plasma. The orientation parameter for direct 1s → 2p±1 excitations in a nonideal plasma is obtained as a function of the impact parameter, the nonideal-plasma parameter, the Debye length, and the projectile energy. The result shows that the nonideal effect reduces the propensity of the 1s → 2p−1 transition. It is also found that the nonideal effect on the orientation parameter increases with increasing projectile energy.

scholarly journals TACHYON DYNAMICS OF THE BLACK DISC LIMIT IN THE HARD SMALL x PROCESSES IN QCD

2006 ◽  
Vol 21 (07) ◽  
pp. 549-558 ◽  
Author(s):  
B. BLOK ◽  
L. FRANKFURT
Keyword(s):  
Cross Section ◽  
Impact Parameter ◽  
High Energy ◽  
Black Disk ◽  
Black Disc ◽  
Energy Behavior ◽  
Small X ◽  
The Cross ◽  
The Impact ◽  
Black Disc Limit

We investigate the effective field theory (EFT) which gives the approximate description of the scattering of two hard small dipoles in the small x processes in QCD near the black disc limit (BDL). We argue that the perturbative QCD approaches predict the existence of tachyon and visualize it in the approximation where α′P=0. We demonstrate that the high energy behavior of the cross-section depends strongly on the diffusion law in the impact parameter plane. On the other hand, almost threshold behavior of the cross section of the hard processes and multiplicities, i.e. fast increase of cross sections (color inflation), melting of ladders into color network and softening of the longitudinal distributions of hadrons are qualitatively insensitive to the value of diffusion in the impact parameter space. We evaluate α′P near the black disk limit and find significant α′P as the consequence of the probability conservation.

scholarly journals Impact Parameter Dependence ofπ-/π+Ratio in Probing the Nuclear Symmetry Energy Using Heavy-Ion Collisions

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Gao-Feng Wei ◽  
Guo-Qiang He ◽  
Xin-Wei Cao ◽  
Yi-Xin Lu
Keyword(s):  
Impact Parameter ◽  
Symmetry Energy ◽  
Heavy Ion Collisions ◽  
Transport Model ◽  
Heavy Ion ◽  
Parameter Dependence ◽  
Central Collisions ◽  
Ion Collisions ◽  
Peripheral Collisions ◽  
The Impact

The impact parameter dependence ofπ-/π+ratio is examined in heavy-ion collisions at 400 MeV/nucleon within a transport model. It is shown that the sensitivity ofπ-/π+ratio on symmetry energy shows a transition from central to peripheral collisions; that is, the stiffer symmetry energy leads to a largerπ-/π+ratio in peripheral collisions while the softer symmetry energy always leads this ratio to be larger in central collisions. After checking the kinematic energy distribution ofπ-/π+ratio, we found this transition of sensitivity ofπ-/π+ratio to symmetry energy is mainly from less energetic pions; that is, the softer symmetry energy gets the less energetic pions to form a smallerπ-/π+ratio in peripheral collisions while these pions generate a largerπ-/π+ratio in central collisions. Undoubtedly, the softer symmetry energy can also lead more energetic pions to form a largerπ-/π+ratio in peripheral collisions. Nevertheless, considering that most of pions are insufficiently energetic at this beam energy, we therefore suggest theπ-/π+ratio as a probe of the high-density symmetry energy effective only in central at most to midcentral collisions, thereby avoiding the possible information of low-density symmetry energy carried inπ-/π+ratio from peripheral collisions.

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