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G. M. Zinovjev

Publications and source records attributed to G. M. Zinovjev.

90 records · Page 5Linked to original sources
arXiv2000

On the origin of current quark mass within nonperturbative QCD

We develop the theory of fermion induced phononlike excitations of the instanton liquid. It suggests a mechanism of current quark mass generation which is easily understandable by calculating the corresponding functional integral in the tadpole approximation. We systematically study the quark condensate excitations influenced by the phononlike modes and rederive the relation Gell-Mann-Oakes-Renner with realistic pion mass. The picture of $σ$-meson as being mixed with the soft scalar glueball-like excitation is discussed.

hep-ph↗
arXiv2000

Photoproduction constraints on J/psi-nucleon interactions

Using J/psi and open charm photoproduction data, we apply the vector meson dominance model to obtain constraints on the energy dependence of the inelastic J/psi-nucleon cross section. Predictions of short distance QCD are in accord with these constraints, while recently proposed hadronic models for J/psi dissociation strongly violate them.

hep-ph↗
arXiv1999

Phononlike Excitations of Instanton Liquid and New Scale of Non-perturbative QCD

The phononlike excitations of (anti-)instanton ($\bar II$) liquid due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and the proper effective Lagrangian for such excitations is evaluated. The properties of their spectrum, while corresponding masses are defined by $Λ_{QCD}$, are investigated.

hep-ph↗
arXiv1999

Potential between adjoint sources in arbitrary representations

The potential between sources in arbitrary representations of the gauge group is studied on an anisotropic lattice in a spherical model approximation. It is shown analytically that for half-integer $j$ and $j'$ in the confinement phase the potential rises linearly, whereas for integer $j$ and half-integer $j'$ it rises infinitely which means a strong suppression of the combination of such states . For integer $j$ and $j'$ the potential shows Debay screening and Coulomb behavior in the deconfinement phase >. It is also shown, that $<χ^{(j)}> \backsim <χ>^{2j}$ when $<χ> \gtrsim1$ and is in agreement with the mean field theory prediction, and $<χ^{(j)}> \backsim <χ>$ for $<χ> \lesssim1$ which agrees with MC experiment. String tension model-computed for sources invariant under center group transformations demonstrates Casimir scaling in the intermediate distance regime and turns into zero at large distances.

hep-lat↗
arXiv1999

The Influence of High Multiplicities at RHIC on the Gamov Factor

The corrections for two-pion correlations due to electromagnetic final-state interactions at high secondary multiplicities are investigated. The analysis is performed by solving the Schrödinger equation with a potential which is dictated by the multi-particle environment. Two different post-freeze-out scenarios are examined. First, for a uniformly spread environment of secondary particles, a screened Coulomb potential is exploited. It is shown that the presence of a static and uniform post-freeze-out medium results in a noticeable deviation from the standard Gamov factor. However, after going to a more realistic model of an expanding pion system, this conclusion changes drastically. We argue that the density of the secondary pions n_π(t,R), where R is a distance from the fireball, is bounded from above by n_π(t,R)\le const/R^2 for all times t. Then, a two-particle scalar potential which is found as a solution of the Maxwell equation for non-uniform medium replaces the screened one. Even this upper limit does not result in an essential deviation from the Gamov correction.

nucl-th↗
arXiv1999

Towards Phonon-Like Excitations of Instanton Liquid

The phonon-like excitations of (anti)-instanton ($\bar II$) liquid due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and the proper effective Lagrangian for such excitations is evaluated. The properties of their spectrum, while corresponding masses are defined by $Λ_{QCD}$, are investigated.

hep-ph↗
arXiv1998

Statistical Aspects of Neveu and Schwarz Dual Model

Statistical method is applied to Neveu and Schwartz model for obtaining the average characteristics of the heavy resonances: spin distribution, decay widths etc. The properties of the dual model spectrum of states constructed of both commuting and anticommuting operators are considered. In this case the spin characteristics coincide with the results of the statistical bootstrap model.

hep-th↗
arXiv1998

Phonon-Like Excitations of the Instanton Liquid

The phonon-like excitations of (anti)-instanton liquid ($\bar II$) due to adiabatic variations of vacuum wave functions are studied in this paper. The kinetic energy term is found and proper effective Lagrangian for such excitations is evaluated.The properties of their spectrum, while the corresponding masses are defined by $Λ_{QCD}$ with prevailing chromoelectric component, are investigated based on the phenomenology of QCD vacuum already developed.

hep-ph↗
arXiv1998

Simple Mechanism of Softening Structure Functions at Low Transverse Momentum Region

The relevance of the dipole configurations of quarks in forming nucleus structure functions is discussed. It is shown that a radiation generated by dipole configurations while moving relativistically along their axises is described by distributions which are finite and infrared stable in low transverse momentum region. It is argued that there is an exponential transition to the perturbative regime of large transverse momenta and its power is defined by the distance between the dipole charges in its rest frame $m^{-1}_π$.

hep-ph↗
arXiv1996

Asymmetry Parameter Role in Description of Phase Structure of Lattice Gluodynamics at Finite Temperature

The role of lattice asymmetry parameter in description of the SU(2) gluodynamics phase structure at finite temperature is studied analytically. The fact that renormalization group relations which permit to remove the lattice asymmetry parameter from the thermodynamical quantities in the "naive" limit don't do the same in the approximation SU(N) = Z(N) keeping the "naive" limit results at the same time was point out. An additional condition which would fix asymmetry parameter is needed for this dependence removal.

hep-lat↗
arXiv1996

Phase structure and confinement properties of noncompact gauge theories II. Z(N) Wilson loop and effective noncompact model

An approach to studying lattice gauge models in the weak coupling region is proposed. Conceptually, it is based on the crucial role of the original Z(N) symmetry and the invariant gauge group measure. As an example, we calculate an effective model from the compact Wilson formulation of the SU(2) gauge theory in $d=3D3$ dimensions at zero temperature. Confining properties and phase structure of the effective model are studied in details.

hep-lat↗
arXiv1995

Coulomb Final State Interaction in Pion Interferometry for the Processes of High Multiplicity

The corrections for two pion correlations due to electromagnetic final state interactions at high secondary multiplicities are investigated. It is shown that these result in a noticeable deviation from the standard Gamov factor. This conclusion changes drastically in a model of the pion system with expansion. The critical parameter which determines the size of these effects is found to be the ratio of the relative velocity of detected pions to the velocity of the pair center-of-mass (in the fireball rest frame). In particular, when this parameter is much less than unity the pion pair escapes the initial high density region promptly and the distortion of the mutual Coulomb potential is weak.

hep-ph↗
arXiv1995

Phase structure and confinement properties of noncompact gauge theories I

In the context of reviewing noncompact lattice gauge models at zero and finite temperature we study in detail a contribution of the invariant measure and the time-like plaquette configurations to correlation functions, analyze the problem of the compactness of the potentials in respect to the confinement and indicate the essential features to deal with the Wilson gauge theory in the weak coupling region. A method for calculating an effective confining noncompact model is also proposed.

hep-lat↗
arXiv1994

On the Deconfinement Phase Transition in the Resonance Gas

We obtain the constraints on the ruling parameters of the dense hadronic gas model at the critical temperature and propose the quasiuniversal ratios of the thermodynamic quantities. The possible appearence of thermodynamical instability in such a model is discussed.

hep-ph↗
arXiv1993

Induced Chern-Simons term in lattice QCD at finite temperature

The general conditions for the Chern-Simons action to be induced as a nonuniversal contribution of fermionic determinant are formulated in the finite temperature lattice QCD. The dependence of the corresponding action coefficient on nonuniversal parameters (chemical potentials, vacuum features, etc. ) is explored. Special attention is paid to the role of $A_0$-condensate if it is available in this theory.

hep-lat↗
arXiv1993

Particles with distance dependent statistics at low temperatures

We consider a simplified model of particles with effectively distance dependent statistics, that is particles coupled to a gauge field the Lagrangian of which contains the Chern-Simons term. We analyze the low-lying states of the two-particle system and show that under certain conditions they can exhibit negative compressibility, hinting on a possible à la van der Vaals picture.

hep-th↗
arXiv1993

Dissipative Processes in an Expanding Massive Gluon Gas

The temperature dependence of the kinetic coefficients is obtained in the non-perturbative region with the help of Green-Kubo-type formulae in the model of massive gluon gas motivated by numerical results from simulations of lattice QCD. The entropy production rate is estimated using scaling hydrodynamics. It is shown that the increase in the viscosity coefficients leads to entropy generation in heavy ion collision processes which could be big, especially for temperatures close to the critical one.

hep-ph↗