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M. N. Chernodub

Publications and source records attributed to M. N. Chernodub.

At least 163 records · Page 9Linked to original sources
arXiv2003

Monopoles in Abelian Polyakov gauge and projection (in)dependence of the dual superconductor mechanism of confinement

We discuss the effect of the choice of an Abelian projection on the dual superconductor mechanism of confinement in SU(2) gluodynamics. Using qualitative arguments we show that the dual superconductor Lagrangian corresponding to the Abelian Polyakov gauge has a different structure compared to the dual Lagrangian in the Maximal Abelian gauge. A difference between these Lagrangians reflects the fact that in continuum limit the monopoles should be static in the Abelian Polyakov gauge and therefore these monopoles can not give rise to the confinement of static quarks. Using the Abelian Polyakov gauge as an example, we show that (i) the dual superconductor scenario of confinement may depend on the Abelian projection; (ii) the condensation of the Abelian monopoles - which may be realized in any Abelian projection - is necessary but not sufficient condition for confinement. These results do not exclude an existence of a class of Abelian gauges in which the dual superconductor scenario works well.

hep-lat↗
arXiv2003

Numerical study of gluon propagators in Maximally Abelian gauge

Propagators of diagonal and off-diagonal gluons are studied numerically in the Maximally Abelian gauge of the SU(2) lattice gauge theory. We have found the strong enhancement of the diagonal gluon in the infrared region. The enhancement factor is about 50 at the smallest available momentum, 325 MeV. We discuss also various analytical fits to the propagators.

hep-lat↗
arXiv2003

Determination of monopole condensate from monopole action in quenched SU(2) QCD

We study the effective monopole action obtained in the Maximal Abelian projection of quenched SU(2) lattice QCD. We determine the quadratic part of the lattice action using analytical blocking from continuum dual superconductor model to the lattice model. The leading contribution to the quadratic action depends explicitly on value of the monopole condensate. We show that the analytical monopole action matches the numerically obtained action in quenched SU(2) QCD with a good accuracy. The comparison of numerical and analytical results gives us the value of the monopole condensate in quenched SU(2) QCD, 243(42) MeV.

hep-lat↗
arXiv2003

Gluodynamics in External Field: A Test of the Dual Superconductor Picture

We study gluodynamics in an external Abelian electromagnetic field within the dual superconductor approach. We show that the SU(2) gluodynamics should possess a deconfining phase transition at zero temperature at certain value of the external field. A dual superconductor model for the SU(3) gauge theory in external field predicts a rich phase structure containing confinement, asymmetric confinement and deconfinement phases. These results can be used to check the validity of the dual superconductor description of gluodynamics in external fields. We also discuss the gauge-independence of the obtained results.

hep-lat↗
arXiv2003

Entropy of monopoles from percolating cluster in quenched SU(2) QCD

The length distribution and the monopole action of the infrared monopole clusters are studied numerically in quenched SU(2) QCD. We determine the effective entropy of the monopole currents which turns out to be a descending function of the blocking scale, indicating that the effective degrees of freedom of the extended monopoles are getting smaller as the blocking scale increases.

hep-lat↗
arXiv2003

An Abelian effective action reproducing screening and confinement in quenched SU(2) QCD

In an Abelian projection SU(2) gluodynamics contains Abelian gauge fields (diagonal degrees of freedom) and Abelian matter fields (off-diagonal degrees). The matter fields are essential for the breaking of the adjoint string. We obtain numerically the effective action of the Abelian fields in quenched SU(2) QCD and show that the Abelian matter fields provide an essential contribution to the total action even in the infrared region.

hep-lat↗
arXiv2003

Numerical determination of monopole entropy in pure SU(2) QCD

We study numerically the length distributions of the infrared monopole clusters in pure SU(2) QCD. These distributions are Gaussian for all studied blocking steps of monopoles, lattice volumes and lattice coupling constant. We also investigate the monopole action for the infrared monopole clusters. The knowledge of both the length distribution and the monopole action allows us to determine the effective entropy of the monopole currents. The entropy is a descending function of blocking scale, indicating that the effective degrees of freedom of the extended monopoles are getting smaller as the blocking scale increases.

hep-lat↗
arXiv2003

Confinement and the photon propagator in 3D compact QED: a lattice study in Landau gauge at zero and finite temperature

On the lattice we study the gauge boson propagator of three dimensional compact QED in Landau gauge at zero and non-zero temperature. The non-perturbative effects are taken into account by the generation of a mass, by an anomalous dimension and by the photon wave function renormalization. All these effects can be attributed to the monopoles: they are absent in the propagator of the singularity-free part of the gauge field. We assess carefully the Gribov copy problem for the propagator and the parameters emerging from the fits.

hep-lat↗
arXiv2003

Confinement, deconfinement and the photon propagator in 3D cQED on the lattice

We report on a lattice study of the gauge boson propagator of 3D compact QED in Landau gauge at zero and finite temperature. Non-perturbative effects are reflected by the generation of a mass m and by an anomalous dimension alpha. These effects can be attributed to monopoles and are absent in the propagator of the regular part of the gauge field.

hep-lat↗
arXiv2002

Monopole creation operators as confinement--deconfinement order parameters

We study numerically two versions of the monopole creation operators proposed by Frohlich and Marchetti. The disadvantage of the old version of the monopole creation operator is due to visibility of the Dirac string entering the definition of the creation operator in the theories with coexisting electric and magnetic charges. This problem does not exist for the new creation operator which is rather complicated. Using the Abelian Higgs model with a compact gauge field we show that both definitions of the monopole creation operator can serve as order parameters for the confinement--deconfinement phase transition. The value of the monopole condensate for the old version depends on the length of Dirac string. However, as soon as the length is fixed the old operator certainly discriminates between the phases with condensed and non--condensed monopoles.

hep-lat↗
arXiv2002

More on String Breaking in the 3D Abelian Higgs Model: the Photon Propagator

We study the Landau gauge photon propagator in the three--dimensional Abelian Higgs model with compact gauge field and fundamentally charged matter in the London limit. The total gauge field is split into singular and regular parts. On the confinement side of the string breaking crossover the momentum dependence of the total propagator is characterized by an anomalous dimension similarly to 3D compact QED. At the crossover and throughout the Higgs region the anomalous dimension disappears. This result perfectly agrees with recent observations that the monopole--antimonopole plasma leads to nonzero anomalous dimension and the presence of the matter fields causes monopole pairing into dipole bound states. The Yukawa mass characterizing the propagator part from regular gauge fields is non-vanishing at the Higgs side and coincides with the mass found for the total propagator. The regular gauge field without anomalous dimension becomes massless at the crossover and in the confinement region.

hep-lat↗
arXiv2002

Towards understanding structure of the monopole clusters

We consider geometrical characteristics of monopole clusters of the lattice SU(2) gluodynamics. We argue that the polymer approach to the field theory is an adequate means to describe the monopole clusters. Both finite-size and the infinite, or percolating clusters are considered. We find out that the percolation theory allows to reproduce the observed distribution of the finite-size clusters in their length and radius. Geometrical characteristics of the percolating cluster reflect, in turn, the basic properties of the ground state of a system with a gap.

hep-th↗
arXiv2002

String breaking and monopoles

The string breaking is discussed in U(1)^{N-1} Abelian effective theories of QCD. When a screening is expected, the static potential shows a flattening in the long-range region and a linear behavior in the intermediate region. We show why the screening is better observed in the Polyakov-loop correlators than in the Wilson loops. The breaking of the adjoint string is explained without the Z(N) picture.

hep-lat↗
arXiv2002

Gluodynamics in external field in dual superconductor approach

We show that gluodynamics in an external Abelian electromagnetic field should possess a deconfining phase transition at zero temperature. Our analytical estimation of the critical external field is based on the dual superconductor picture which is formulated in the Euclidean space suitable for lattice calculations. A dual superconductor model corresponding to the SU(2) gluodynamics possesses confinement and deconfinement phases below and, respectively, above the critical field. A dual superconductor model for the SU(3) gauge theory predicts a rich phase structure containing confinement, asymmetric confinement and deconfinement phases. The quark bound states in these phases are analyzed. Inside the baryon the strings are Y--shaped as predicted by the dual superconductor picture. This shape is geometrically asymmetric in the asymmetric confinement phases. The results of the paper can be used to check the dual superconductor mechanism in gluodynamics.

hep-ph↗
arXiv2002

String Breaking and Monopoles: a Case Study in the 3D Abelian Higgs Model

We study the breaking of the string spanned between test charges in the three dimensional Abelian Higgs model with compact gauge field and fundamentally charged Higgs field at zero temperature. In agreement with current expectations we demonstrate that string breaking is associated with pairing of monopoles. However, the string breaking is not accompanied by an ordinary phase transition.

hep-lat↗
arXiv2002

Anatomy of the lattice magnetic monopoles

We study the Abelian and non-Abelian action densitynear the monopole in the maximal Abelian gauge of SU(2) lattice gauge theory. We find that the non-Abelian action density near the monopoles belonging to the percolating cluster decreases when we approach the monopole center. Our estimate of the monopole radius is R_mon ~ 0.04 fm.

hep-lat↗
arXiv2002

Monopoles, confinement and the photon propagator in QED$_3$

We study the lattice gauge boson propagator of 3D compact QED in Landau gauge at zero and non-zero temperature. Non-perturbative effects are reflected by the generation of a mass $m$, by an anomalous dimension $α$ and by the photon wave function renormalisation $Z$. These effects can be attributed to monopoles: they are absent in the propagator of the regular part of the gauge field. The rôle of Gribov copies is carefully investigated.

hep-lat↗