arXiv subjects
Publications and source records attributed to S. V. Molodtsov.
The effect of external colour field impact on the instanton liquid is studied. In the course of this study the corresponding effective Lagrangians are derived for both regimes of weak and strong external field and in long wave-length approximation. The example of Euclidean colour point-like source is analyzed in detail and the feedback of field on the instanton liquid is estimated as a function of source intensity.
{(Anti-)instanton behaviour in Euclidean non-abelian field of the point-like source is studied by analyzing the possible (anti-)instanton deformations as resulted from the variations of its characteristic parameters. The variational principle for searching such crumpled topological configurations is formulated and the problem is resolved then algebraically by the Ritz method (multipole expansion of the deformation fields). The region of (anti-)instanton parameters relevant to the instanton liquid model is investigated in detail. The approximate efficacious method to include such configurations contributing to the appropriate partition function is proposed and verified. Evaluating average energy of Euclidean non-abelian point-like source in the instanton environment (liquid) is performed within the superposition ansatz for the corresponding solutions of the Yang-Mills equations. For the colour singlet dipole this energy escalates linearly with the separation increasing and its tension coefficient develops the magnitude commensurate with that as inferred from lattice QCD.
Estimate of average energy of the non-abelian dipole in the instanton medium is calculated. This energy for the dipole in colour singlet state escalates linearly with the separation increasing for the point-like sources unscreened. And its 'tension' coefficient develops the magnitude pretty similar to one as inferred from the lattice QCD and other model approaches.
An appraisal of average energy of Euclidean non-abelian point-like source in the instanton liquid is calculated. It behaves linearly increasing at large distances while unscreened. For the dipole in colour singlet state this energy increases linearly again with the separation increasing and its "tension" coefficient develops the magnitude pretty similar to the lattice approach and other model estimates. The situation of sources arbitrary oriented in colour space is perturbatively considered.
The interaction of light quarks and instanton liquid is analyzed at finite density of quark/baryon matter and in the phase of nonzero values of diquark (colour) condensate. It is shown that instanton liquid perturbation produced by such an interaction results in an essential increase of the critical value of quark chemical potential $μ_c$ which provokes the perceptible increase of quark matter density around the expected onset of the colour superconductivity phase.
We study light quark interactions in the instanton liquid at finite quark/baryon number density analyzing chiral and diquark condensates and investigate the behaviors of quark dynamical mass and both condensates together with instanton liquid density as a function of quark chemical potential. We conclude the quark impact (estimated in the tadpole approximation) on the instanton liquid could shift color superconducting phase transition to higher values of the chemical potential bringing critical quark matter density to the values essentially higher than conventional nuclear one.
The interaction of light quarks and instanton liquid is analyzed at finite density of quark/baryon matter and in the phase of nonzero values of diquark (colour) condensate. It is shown that instanton liquid perturbation produced by such an interaction results in an essential increase of the critical value of quark chemical potential $μ_c$ which provokes the perceptible increase of quark matter density around the expected onset of the colour superconductivity phase.
The interaction of light quarks and instanton liquid in the phase of nonzero values of chiral condensate is studied at finite quark/baryon density. Calculating the generating functional in the tadpole approximation we investigate the behaviour of dynamical quark mass and chiral condensate together with instanton liquid density (which shows insignificant increase) as a function of quark/baryon chemical potential. We argue on the noticeable increase of quark density at the point of developing the nonzero magnitude of diquark condensate due only to the quark interaction with the instanton liquid.
The selfconsistent approach to the quark interactions in the instanton liquid is developed within the tadpole approximation calculating the basic functional integral. The effective Lagrangian obtained includes colourless scalar field interacting with quarks. The origin of this dynamical field as an interaction carrier in soft momentum region is discussed.
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.
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.
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.
Finite temperature SU(2) lattice gauge theory is investigated in a 3D cubic box with fixed boundary conditions provided by a discretized, static BPS monopole solution with varying core scale $μ$. Using heating and cooling techniques we establish that for discrete $μ$-values stable classical solutions either of self-dual or of pure magnetic type exist inside the box. Having switched on quantum fluctuations we compute the Polyakov line and other local operators. For different $μ$ and at varying temperatures near the deconfinement transition we study the influence of the boundary condition on the vacuum inside the box. In contrast to the pure magnetic background field case, for the self-dual one we observe confinement even for temperatures quite far above the critical one.
Finite temperature SU(2) lattice gauge theory is investigated in a 3D cubic box with fixed boundary conditions (b.c.) provided by a discretized, static BPS monopole solution with varying core scale $μ$. For discrete $μ$-values we find stable classical solutions either of electro-magnetic ('dyon') or of purely magnetic type inside the box. Near the deconfinement transition we study the influence of the b.c. on the quantized fields inside the box. In contrast to the purely magnetic background field case, for the dyon case we observe confinement for temperatures above the usual critical one.
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.
Field strength correlators are semi-classically evaluated in the dilute gas model of non-Abelian sources (instantons) and compared with lattice data for QCD at zero temperature. We show that one of the Euclidean invariant, tensorial structures vanishes for configurations being purely selfdual or anti-selfdual. We compute the invariant functions contributing to the correlators within the two lowest orders in an instanton density expansion. Fitting instanton size and density for quenched and full QCD, we obtain a reasonable description.
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 $m^{-1}_π$.
The problem of two nonrelativistic chromoelectric and chromomagnetic charges in a Higgs vacuum is considered in classical field theory. An approximation of interaction potential is constructed on the basis of a numerical solution to the equations of gluostatics. The concept of a non-Abelian Abrikosov vortex is discussed. It is shown that the results of Ginzburg-Landau theory for the tension of a string between magnetic charges can be directly extended to the non-Abelian case.