Study of thermal monopoles in lattice QCD (original) (raw)
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Magnetic monopoles in the high temperature phase of Yang–Mills theories
Nuclear Physics B, 2008
We investigate the properties of thermal abelian magnetic monopoles in the high temperature phase of Yang-Mills theories, following a recent proposal for their identification on lattice configurations. The study is done for SU(2) pure gauge theory, for temperatures going up to about 10 times the deconfining temperature and using the Maximal Abelian gauge to perform the abelian projection. We find that the monopole density has a well defined continuum limit. Its temperature dependence disagrees with a free particle gas prediction and is instead well described by a T 3 /(log(T /Λ)) α behaviour in all the explored range, with α ∼ 2 and Λ ∼ 100 MeV. Also the study of spatial correlations of thermal monopoles shows the presence of non-trivial interactions among them. Finally, we discuss the gauge dependence of our results, showing that it is significant and that, even within the Maximal Abelian gauge, Gribov copy effects are important.
Thermal Abelian monopoles as self-dual dyons
Physical Review D, 2011
The properties of the thermal Abelian monopoles are studied in the deconfinement phase of the SU (2) gluodynamics. To remove effects of Gribov copies the simulated annealing algorithm is applied to fix the maximally Abelian gauge. To study monopole profile we complete the first computations of excess of the nonabelian action density as a function of the distance from the center of the thermal Abelian monopole. We have found that starting from the distances ≈ 2 lattice spacings the chromoelectric and chromomagnetic action densities created by monopole are equal to each other, from what we draw a conclusion that monopole is a dyon. Furthermore, we find that the chromoelectric and chromomagnetic fields decrease exponentially with increasing distance. These findings were confirmed for different temperatures in the range T /Tc ∈ (1.5, 4.8).
Study of the thermal Abelian monopoles with proper gauge fixing
Physical Review D, 2012
The properties of the thermal abelian monopoles are studied in the deconfinement phase of the SU (2) gluodynamics. To remove effects of Gribov copies the simulated annealing algorithm is applied to fix the maximally abelian gauge. Computing the density of the thermal abelian monopoles in the temperature range between 1.5 Tc and 6.9 Tc we show, by comparison with earlier results, that the Gribov copies effects might be as high as 20% making proper gauge fixing mandatory. We find that in the infinite temperature limit the monopole density converges to its value in 3-dimensional theory. To study the interaction between monopoles we calculate the monopole-monopole and monopoleantimonopole correlators at different temperatures in the region (1.5 Tc, 6.9 Tc). Using the result of this study we determine the screening mass, monopole-monopole coupling constant, monopole size and monopole mass. In addition we check the continuum limit of our results.
Thermal monopole condensation and confinement in finite temperature Yang-Mills theories
Physical Review D, 2010
We investigate the connection between Color Confinement and thermal Abelian monopoles populating the deconfined phase of SU(2) Yang-Mills theory, by studying how the statistical properties of the monopole ensemble change as the confinement/deconfinement temperature is approached from above. In particular we study the distribution of monopole currents with multiple wrappings in the Euclidean time direction, corresponding to two or more particle permutations, and show that multiple wrappings increase as the deconfinement temperature is approached from above, in a way compatible with a condensation of such objects happening right at the deconfining transition. We also address the question of the thermal monopole mass, showing that different definitions give consistent results only around the transition, where the monopole mass goes down and becomes of the order of the critical temperature itself.
Confined magnetic monopoles in dense QCD
Physical Review D, 2011
Non-Abelian strings exist in the color-flavor locked phase of dense QCD. We show that kinks appearing in the world-sheet theory on these strings, in the form of the kink-antikink bound pairs, are the magnetic monopoles -descendants of the 't Hooft-Polyakov monopoles surviving in such a special form in dense QCD. Our consideration is heavily based on analogies and inspiration coming from certain supersymmetric non-Abelian theories. This is the first ever analytic demonstration that objects unambiguously identifiable as the magnetic monopoles are "native" to non-Abelian Yang-Mills theories (albeit our analysis extends only to the phase of the monopole confinement and has nothing to say about their condensation). Technically our demonstration becomes possible due to the fact that low-energy dynamics of the non-Abelian strings in dense QCD is that of the orientational zero modes. It is described by an effective two-dimensional CP (2) model on the string world sheet. The kinks in this model representing confined magnetic monopoles are in a highly quantum regime.
On the dynamics of color magnetic monopoles in full QCD
Nuclear Physics B - Proceedings Supplements, 2002
We present first results on the dynamics of monopoles in full QCD with N f = 2 flavors of dynamical quarks. Among the quantities being studied are the monopole density and the monopole screening length, the static potential as well as the profile of the color electric flux tube. Furthermore, we derive the low-energy effective monopole action. * Talks given by H. Ichie, Y. Koma and T. Streuer at Lattice 2001, Berlin, Germany. † On leave of absence from IHEP, Protvino, Russia.
Proceedings of The XXVI International Symposium on Lattice Field Theory — PoS(LATTICE 2008), 2009
We propose a new description of the SU(N) Yang-Mills theory on a lattice, which enables one to explain quark confinement based on the dual superconductivity picture in a gauge independent way. This is because we can define gauge-invariant magnetic monopoles which are inherent in the Wilson loop operator. For SU(3) there are two options: the minimal option with a single type of non-Abelian magnetic monopole characterized by the maximal stability subgroupH = U(2) = SU(2) ×U(1), and the maximal one with two types of Abelian magnetic monopoles characterized by the maximal torus subgroupH = U(1) ×U(1). The maximal option corresponds to a gauge independent reformulation of the Abelian projection represented by the conventional MAG. In the minimal option, we have successfully performed the numerical simulation of the SU(3) Yang-Mills theory on a lattice. We give preliminary numerical results showing the dominance of the non-Abelian magnetic monopole in the string tension obtained from the Wilson loop in the fundamental representation, and the infrared dominance of a decomposed field variable for correlation functions after demonstrating the preservation of color symmetry which was explicitly broken by the conventional MAG.
A gauge invariant study of the monopole condensation in non Abelian lattice gauge theories
2000
We investigate the Abelian monopole condensation in finite temperature SU(2) and SU(3) pure lattice gauge theories. To this end we introduce a gauge invariant disorder parameter built up in terms of the lattice Schr\"odinger functional. Our numerical results show that the disorder parameter is different from zero and Abelian monopole condense in the confined phase. On the other hand our numerical data suggest that the disorder parameter tends to zero, in the thermodynamic limit, when the gauge coupling constant approaches the critical deconfinement value. In the case of SU(3) we also compare the different kinds of Abelian monopoles which can be defined according to the choice of the Abelian subgroups.