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O. K. Kalashnikov

Publications and source records attributed to O. K. Kalashnikov.

15 recordsLinked to original sources
arXiv1998

Fermi spectra and their gauge invariance in hot and dense Abelian and non-Abelian theories

The one-loop Fermi spectra (one-particle and collective ones) are found for all momenta in the $T^2$-approximation and their gauge invariance in hot and dense Abelian and non-Abelian theories is studied. It is shown that the one-particle spectrum, if the calculation accuracy is kept strictly, is gauge invariant for all momenta and has two branches as the bare one. The collective spectrum always has four branches which are gauge dependent including also their $|\q|=0$ limit. The exception is the case $m,μ=0$ for which this spectrum is gauge invariant for all momenta as well.

hep-ph↗
arXiv1998

One-particle and collective electron spectra in hot and dense QED and their gauge dependence

The one-particle electron spectrum is found for hot and dense QED and its properties are investigated in comparison with the collective spectrum. It is shown that the one-particle spectrum (in any case its zero momentum limit) is gauge invariant, but the collective spectrum, being qualitatively different, is always gauge dependent. The exception is the case $m,μ=0$ for which the collective spectrum long wavelength limit demonstrates the gauge invariance as well.

hep-ph↗
arXiv1998

Photon and electron spectra in hot and dense QED

Photon and electron spectra in hot and dense QED are found in the high temperature limit for all $|\q|$ using the Feynman gauge and the one-loop self-energy. All spectra are split by the medium and their branches develop the gap (the dynamical mass) at zero momentum. The photon spectrum has two branches (longitudinal and transverse) with the common mass; but electron spectrum is split on four branches which are well-separated for any $|\q|$ including their $|\q|=0$ limits (their effective masses). These masses and the photon thermal mass are calculated explicitly and the different limits of spectrum branches are established in detail. The gauge invariance of the high-temperature spectra is briefly discussed.

hep-ph↗
arXiv1997

Collective Excitations of Massive Dirac Particles in Hot and Dense Medium

The one-loop dispersion equation which defines the collective excitations of the massive Dirac particles in hot and dense quark-gluon medium is obtained in the high temperature limit for the case $m<<T$ and solved explicitly for all $|\q|$ when $μ=0$. Four well-separated spectrum branches (quasi-particle and quasi-hole excitations) are found and their behaviors for the small and large $|\q|$ are investigated. All calculations are performed using the temperature Green function technique and fixing the Feynman gauge. The gauge dependency of the spectra found are briefly discussed.

hep-ph↗
arXiv1996

Fermi Excitations in Hot and Dense Quark-Gluon Plasma

The Fermi excitations in hot and dense quark-gluon plasma are studied in the Feynman gauge using the temperature Green function technique. We find the four well-separated branches for the case $m=0$ and establish the additional splitting between them (the four different masses) when $m\ne 0$. The long wavelength limit of these excitations is found in the general case of the massive fermions at finite temperature and densities to give the exact one-loop spectrum. Simultaneously the many known results are reproduces as its different limits.

hep-ph↗
arXiv1996

Hot quark-gluon matter with deconfined heavy quarks

The phase diagram of the quark-gluon matter evolution is presented for the SU(3)-model with a new phase of heavy deconfined quarks which exists in a rather wide range of temperatures and densities. Fitting the chiral phase transition data to fix the model parameters we establish another (deconfinement) phase transition which separates a new phase from hadronic matter. The parameters and properties of the phase diagram are discussed in comparison with lattice and other results.

hep-ph↗
arXiv1996

Magnetic Mass in Hot Scalar Electrodynamics

Using the Slavnov-Taylor identities we prove that the so-called "magnetic mass" is exactly equal to zero within hot scalar electrodynamics. The same result is valid for hot QED and seems for any abelian theory but this is not the case for hot QCD where one expects that $\m\ne 0$.

hep-ph↗
arXiv1995

SELF-ENERGY PECULIARITIES OF THE HOT GAUGE THEORY AFTER SYMMETRY BREAKING

A tensor representation of the gluon propagator is found within covariant gauges for a non-Abelian theory after symmetry breaking due to $ \ne 0$ and the exact equations which determine the dispersion laws of plasma excitations are explicitly obtained. In the high temperature region and fixing the Feynman gauge we solved these equations and found the damping of the plasma oscillations and the shifting of their frequency. The phase transition of a gauge symmetry restoration is estimated to be $α_c(T) \approx{4/3}$.

hep-ph↗
arXiv1995

THE HIGH TEMPERATURE DISPERSION EQUATION FOR LONGITUDINAL PLASMA OSCILLATIONS IN TAG

The calculations in the temporal axial gauge (TAG) are revised and a new prescription is introduced to avoid the well-known TAG-singularity. With this prescription we use the TAG-formalism to calculate the one-loop dispersion equation for the longitudinal plasma oscillations in the high temperature limit and find the complete selfconsistency of TAG for pragmatic aims. Our result reproduces the earlier known dispersion equation obtained in covariant gauges and this equality explicitly demonstrates the gauge independence of the dispersion law in the high temperature limit and its reliability.

hep-ph↗
arXiv1994

Infrared Properties of the Hot Gauge Theory after Symmetry Breaking

It is shown that the fictitious infrared pole is eliminated from the hot gauge theory which acquires a new vacuum after the global gauge symmetry spontaneously breaking. The nonzero W-condensate is generated and leads to the screening of the chromomagnetic forces through the scenario with the standard magnetic mass.

hep-ph↗
arXiv1994

The Nonabelian Screening Potential Beyond the Leading Order

The nonabelian screening potential is calculated in the temporal axial gauge. The Slavnov-Taylor identity is used to construct the three-gluon vertex function from the inverse gluon propagator. After solving the Schwinger - Dyson equation beyond leading order we find that the obtained momentum dependence of the gluon self-energy at high temperature does not correspond to an attractive QCD - Debye potential, but instead it is repulsive and power behaved ($ \simeq 1/r^6$) at large distance.

hep-ph↗
arXiv1994

The Nonperturbative Equation for the Infrared Π_{44}(0) - Limit in the Temporal Axial Gauge

The nonperturbative equation for the infrared $Π_{44}(0)$-limit is built by using the Slavnov-Taylor identity to define the three-gluon vertex function in the temporal axial gauge. We found that all vertex corrections should be taken into account along with the standard ring graphs to keep the gauge covariance throughout calculations and to give correctly the nonperturbative $g^3$-term. This term is explicitly calculated and compared with the previously known results.

hep-ph↗
arXiv1993

Gauge Fields Condensation at Finite Temperature

The two-loop effective action for the SU(3) gauge model in a constant background field ${\bar A}_0(x,t)=B_0^3T_3+B_0^8T_8$ is recalculated for a gauge with an arbitrary $ξ$-parameter. The gauge-invariant thermodynamical potential is found and its extremum points are investigated. Within a two-loop order we find that the stable nontrivial vacuum is completely equivalent to the trivial one but when the high order corrections being taken into account the indifferent equilibrium seems to be broken. Briefly we also discuss the infrared peculiarities and their status for the gauge models with a nonzero condensate.

hep-th↗