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M. A. Zubkov

Publications and source records attributed to M. A. Zubkov.

140 records · Page 8Linked to original sources
arXiv2003

Abelian representation for nonabelian Wilson loops and the Non - Abelian Stokes theorem on the lattice

We derive the Abelian - like expression for the lattice SU(N) Wilson loop in arbitrary irreducible representation. The continuum Abelian representation of the SU(N) Wilson loop (for the loop without selfintersections) that has been obtained by Diakonov and Petrov appears to be a continuum limit of this expression. We also obtain the lattice variant of a non - Abelian Stokes theorem and present the explicit expression for the matrix $\cal H$ used in the Diakonov - Petrov approach.

hep-lat↗
arXiv2003

Effective abelian gauge theory for lattice gluodynamics and chromoelectric string

The lattice SU(2) gluodynamics in the maximal abelian projection is reduced to the abelian theory, in which the natural small parameter exists. We show that in the zeroth order of the expansion in this parameter the theory is equivalent to the compact abelian gauge theory coupled to ghosts of charge 2. The theory is a renormalizable and asymptotically free. This theory is represented in the form of the theory of open string with the boundary consisting of the worldline of the quark. The ghosts live on the worldsheet of the string. The naive continuum limit of such string representation gives a simple expression for the chromoelectric string action.

hep-th↗
arXiv2002

Dirac monopoles embedded into SU(N) gauge theory with $θ$ - term

We consider Dirac monopoles embedded into SU(N) gauge theory with theta-term for $θ= 4πM $ (where $M$ is half-integer for $N = 2$ and is integer for $N>2$). Due to the theta - term those monopoles obtain the SU(N) charge and become the dyons. They belong to different irreducible representations of SU(N) (but not to all of them). The admitted representations are enumerated. Their minimal rank increases with increasing of $N$. The main result of the paper is the representation of the partition function of SU(N) model with theta-term (that contains singular gauge fields correspondent to the mentioned monopoles) as the vacuum average of the product of Wilson loops (considered along the monopole worldlines). This vacuum average should be calculated within the correspondent model without theta-term.

hep-th↗
arXiv2002

Evidence for the reality of singular configurations in SU(2) gauge theory

We consider the SU(2) lattice gauge model and investigate numerically the continuum limit of the simple center vortices which are singular configurations of the gauge fields. We found that the vortices remain alive in the continuum theory. Also we investigate the Creutz ratio and found that for all $β$ it vanishes for those field configurations which do not contain the simple center vortices inside the considered Wilson loop. It leads us to the conclusion that these singular field configurations play a real role in the continuum theory.

hep-lat↗
arXiv2001

Theta term instead of the Higgs field in Electroweak theory

We consider the electroweak theory without fundamental scalar field. The topological excitation of the SU(2)*U(1) theory (the monopole) plays the role of the Higgs field, it carries the SU(2)*U(1) topological charge due to the theta--term of the special type.

hep-lat↗
arXiv2000

The Simple Center Projection of SU(2) Gauge Theory

We consider the SU(2) lattice gauge model. We propose a new gauge invariant definition of center projection, which we call the Simple Center Projection. We demonstrate the center dominance, i.e., the coincidence of the projected potential with the full potential up to the mass renormalization term at low energies. We also consider the center vortices and the center monopoles ({\em nexuses}). It turns out that the behavior of such objects qualitatively coincides with the behavior of the vortices and monopoles in the Maximal Center gauge. The connection of the condensation of nexuses with the dual superconductor theory is discussed. Numerically the procedure of extracting the center vortices proposed in this paper is much simpler than the usual Maximal Center Projection.

hep-lat↗
arXiv1998

Aharonov-Bohm effect, Center Monopoles and Center Vortices in SU(2) Lattice Gluodynamics

SU(2) gluodynamics is investigated numerically and analytically in the (Indirect) Maximal Center gauge at finite temperature. The center vortices are shown to be condensed in the confinement phase and dilute in the deconfinement phase. A new physical object, center monopole, is constructed. We show that the center monopole condensate is the order parameter of deconfinement phase transition. The linking of the vortex worldsheets and quark trajectories is identified with the Aharonov-Bohm interaction in an effective Abelian Higgs theory. We conclude that the confinement in the Maximal Center gauge can be explained by a new mechanism called "the real superconductor mechanism".

hep-lat↗
arXiv1998

Strings and Aharonov-Bohm Effect in Abelian Higgs Model

We investigate numerically the properties of the Abrikosov-Nielsen-Olesen strings in 4D abelian Higgs model. The fractal dimension D_f of the vortex strings was found to be large in the Coulomb phase and it is close to 2 in the Higgs phase. We also show that the Wilson loop for non-integer charges is correlated with the linking number of the vortex string world sheets and the test particle world trajectory. We find that this topological (Aharonov-Bohm) interaction gives the main contribution to the Wilson loop quantum average for non-integer test charges in the vicinity of the Coulomb-Higgs phase transition.

hep-lat↗
arXiv1995

Quantum Theory of Strings in Abelian Higgs Model

Starting from the Abelian Higgs field theory, we construct the theory of quantum Abrikosov--Nielsen--Olesen strings. It is shown that in four space -- time dimensions in the limit of infinitely thin strings, the conformal anomaly is absent, and the quantum theory exists. We also study an analogue of the Aharonov--Bohm effect: the corresponding topological interaction is proportional to the linking number of the string world sheet and the particle world trajectory. The creation operators of the strings are explicitly constructed in the path integral and in the Hamiltonian formulation of the theory. We show that the Aharonov--Bohm effect gives rise to several nontrivial commutation relations.

hep-th↗
arXiv1993

Compact QED in Landau Gauge: a lattice gauge fixing case study

We derive different representations of compact QED fixed to Landau gauge by the lattice Faddeev-Popov procedure. Our analysis finds that (A)Nielsen-Olesen vortices arising from the compactness of the gauge-fixing action are {\it quenched\/}, that is, the Faddeev-Popov determinant cancels them out and they do not influence correlation functions such as the photon propagator; (B)Dirac strings are responsible for the nonzero mass pole of the photon propagator. Since in $D=3+1$ the photon mass undergoes a rapid drop to zero at $β_c$, the deconfinement point, this result predicts that Dirac strings must be sufficiently dilute at $β> β_c$. Indeed, numerical simulations reveal that the string density undergoes a rapid drop to near zero at $β\sim β_c$.

hep-lat↗
arXiv1993

String Representation of the Abelian Higgs Theory and Aharonov-Bohm Effect on the Lattice

The partition function of the $4D$ lattice Abelian Higgs theory is represented as the sum over world sheets of Nielsen--Olesen strings. The creation and annihilation operators of the strings are constructed. The topological long--range interaction of the strings and charged particles is shown to exist; it is proportional to the linking number of the string world sheet and particle world trajectory.

hep-lat↗