scholarly journals Dielectric permeability tensor and linear waves in spin-1/2 quantum kinetics with non-trivial equilibrium spin-distribution functions

2017 ◽  
Vol 24 (11) ◽  
pp. 112108 ◽  
Author(s):  
Pavel A. Andreev ◽  
L. S. Kuz'menkov
Keyword(s):  
Dielectric Permeability ◽  
Distribution Functions ◽  
Permeability Tensor ◽  
Spin Distribution ◽  
Linear Waves ◽  
Quantum Kinetics ◽  
Trivial Equilibrium

scholarly journals CHIRAL QUARK MODEL (χQM) AND THE NUCLEON SPIN

2004 ◽  
Vol 19 (29) ◽  
pp. 5027-5041 ◽  
Author(s):  
HARLEEN DAHIYA ◽  
MANMOHAN GUPTA
Keyword(s):  
Angular Momentum ◽  
Magnetic Moments ◽  
Distribution Functions ◽  
Gluon Polarization ◽  
Spin Distribution ◽  
Polarization Functions ◽  
Singlet Component ◽  
Configuration Mixing ◽  
The Right ◽  
E866 Data

Using χ QM with configuration mixing, the contribution of the gluon polarization to the flavor singlet component of the total spin has been calculated phenomenologically through the relation [Formula: see text] as defined in the Adler–Bardeen scheme, where ΔΣ on the right-hand side is Q2 independent. For evaluation the contribution of gluon polarization [Formula: see text], ΔΣ is found in the χ QM by fixing the latest E866 data pertaining to [Formula: see text] asymmetry and the spin polarization functions whereas ΔΣ(Q2) is taken to be 0.30±0.06 and αs=0.287±0.020, both at Q2=5 GeV 2. The contribution of gluon polarization Δg' comes out to be 0.33 which leads to an almost perfect fit for spin distribution functions in the χ QM . When its implications for magnetic moments are investigated, we find perfect fit for many of the magnetic moments. If an attempt is made to explain the angular momentum sum rule for proton by using the above value of Δg', one finds the contribution of gluon angular momentum to be as important as that of the [Formula: see text] pairs.

scholarly journals Equilibrium Spin Distribution From Detailed Balance

2021 ◽  
Vol 81 (9) ◽  
Author(s):  
Ziyue Wang ◽  
Xingyu Guo ◽  
Pengfei Zhuang
Keyword(s):  
Spin Polarization ◽  
Transport Theory ◽  
Axial Vector ◽  
Detailed Balance ◽  
Kinetic Equations ◽  
Distribution Functions ◽  
Spin Distribution ◽  
Balance Principle ◽  
Quark Level ◽  
Vector Distribution

AbstractAs the core ingredient for spin polarization, the equilibrium spin distribution function that eliminates the collision terms is derived from the detailed balance principle. The kinetic theory for interacting fermionic systems is applied to the Nambu–Jona-Lasinio model at quark level. Under the semi-classical expansion with respect to $$\hbar $$ ħ , the kinetic equations for the vector and axial-vector distribution functions are obtained with collision terms. For an initially unpolarized system, spin polarization can be generated at the first order of $$\hbar $$ ħ from the coupling between the vector and axial-vector charges. Different from the classical transport theory, the collision terms in a quantum theory vanish only in global equilibrium with Killing condition.

On the interaction of adjacent hot plasma streams. I. Dielectric permeability tensor components

1971 ◽  
Vol 13 (10) ◽  
pp. 913-918
Author(s):  
N M El-Siragy ◽  
V I Pakhomov ◽  
K E Zayed
Keyword(s):  
Dielectric Permeability ◽  
Permeability Tensor ◽  
Hot Plasma

scholarly journals REAL TIME NONEQUILIBRIUM DYNAMICS OF QUANTUM PLASMAS: QUANTUM KINETICS AND THE DYNAMICAL RENORMALIZATION GROUP

2001 ◽  
Vol 16 (supp01c) ◽  
pp. 1260-1264
Author(s):  
H. J. de VEGA
Keyword(s):  
Renormalization Group ◽  
Real Time ◽  
Distribution Functions ◽  
Nonequilibrium Dynamics ◽  
Pair Annihilation ◽  
Quantum Plasmas ◽  
Quantum Kinetics ◽  
Mean Fields ◽  
Production Form ◽  
Kinetics Of

We implement the dynamical renormalization group (DRG) using the hard thermal loop (HTL) approximation for the real-time nonequilibrium dynamics in hot plasmas. The focus is on the study of the relaxation of gauge and fermionic mean fields and on the quantum kinetics of the photon and fermion distribution functions. As a concrete physical prediction, we find that for a QGP of temperature T~200 MeV and lifetime 10≤t≤ 50 fm /c there is a new contribution to the hard (k~T) photon production form off-shell bremsstrahlung (q→qγ and [Formula: see text] at just O(α) that grows logarithmically in time and is comparable to the known on-shell Compton scattering and pair annihilation at O(ααs).

scholarly journals Structure Functions of Hadrons in the QCD Effective Theory

1997 ◽  
Vol 50 (1) ◽  
pp. 139
Author(s):  
Takayuki Shigetani ◽  
Katsuhiko Suzuki ◽  
Hiroshi Toki
Keyword(s):  
Quark Distribution ◽  
High Energy ◽  
Structure Functions ◽  
Distribution Functions ◽  
Low Energy ◽  
Effective Theory ◽  
Spin Distribution ◽  
Diquark Model ◽  
Model Calculations ◽  
Diquark Correlation

We study the structure functions of hadrons with the low energy effective theory of QCD. We try to clarify a link between the low energy effective theory, where non-perturbative dynamics is essential, and the high energy deep inelastic scattering experiment. We calculate the leading twist matrix elements of the structure function at the low energy model scale within the effective theory. Calculated structure functions are taken to the high momentum scale with the help of the perturbative QCD, and compared with the experimental data. Through a comparison of the model calculations with the experiment, we discuss how the non-perturbative dynamics of the effective theory is reflected in the deep inelastic phenomena. We first evaluate the structure functions of the pseudoscalar mesons using the NJL model. The resulting structure functions show reasonable agreement with experiments. We then study the quark distribution functions of the nucleon using a covariant quark–diquark model. We calculate three leading twist distribution functions, the spin-independent f1(x), the longitudinal spin distribution g1(x), and the chiral-odd transversity spin distribution h1(x). The results for f1(x) and g1(x) turn out to be consistent with available experiments because of the strong spin-0 diquark correlation.

Non-linear waves in a non-uniform plasma

1972 ◽  
Vol 7 (1) ◽  
pp. 49-65 ◽  
Author(s):  
R. J. Gribben
Keyword(s):  
Averaging Method ◽  
Relativistic Effects ◽  
Perturbation Parameter ◽  
Order Theory ◽  
Distribution Functions ◽  
Necessary Condition ◽  
General Boundary Condition ◽  
Leading Order ◽  
Linear Waves ◽  
Non Linear

The work of Butler & Gribben (1968) on a general formulation ofthe problem of non-linear waves in non-uniform plasmas is extended. The particular case treated in Butler & Gribben, § 6, is discussed again (the distribution functions fs and electrostatic potential depend only on one space co-ordinate, that in the direction of propagation of the wave, the wave is slowly varying only with respect to this co-ordinate and time, the magnetic field vanishes and relativistic effects are negligible). Conditions necessary to avoid secular terms in the solutions of the Vlasov and Poisson equations are rederived, but without resorting to assumed series expansions in e, the perturbation parameter describing the non-uniformity, for the dependent variables, and using a different notation which simplifies and retains the symmetry of the equations. The corresponding general boundary condition, to be satisfied by fs innergy space at the boundary of the trapped particle region, is also derived.Particular attention is devoted to the Vlasov equation, and the derived general result is used to obtain the appropriate necessary condition from this equation, correct to O(ε). This shows that, unlike the leading-order theory, at the next stage an extra length scale appears in the equations, which would be needed if e.g. the theory were to be used to discuss shock waves. It is argued that this result, taken with the mixing process described in Butler & Gribben (which supplies a mechanism for the formation of shocks), appears to place the theory at least on as satisfactory a level as the Navier-Stokes theory for the discussion of shock wave structures.Another aspect of the analysis is the comparison with the Whitham (1965a) averaging method for treating the propagation of non-linear waves in other fields. Similar features are pointed out, and it seems likely that the averaging method is equivalent to the leading-order theory. It is thought that the present approach might prove to be useful in other wave problems.

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