17,716 research outputs found
Yang-Mills theory constructed from Cho--Faddeev--Niemi decomposition
We give a new way of looking at the Cho--Faddeev--Niemi (CFN) decomposition
of the Yang-Mills theory to answer how the enlarged local gauge symmetry
respected by the CFN variables is restricted to obtain another Yang-Mills
theory with the same local and global gauge symmetries as the original
Yang-Mills theory. This may shed new light on the fundamental issue of the
discrepancy between two theories for independent degrees of freedom and the
role of the Maximal Abelian gauge in Yang-Mills theory. As a byproduct, this
consideration gives new insight into the meaning of the gauge invariance and
the observables, e.g., a gauge-invariant mass term and vacuum condensates of
mass dimension two. We point out the implications for the Skyrme--Faddeev
model.Comment: 17pages, 1 figure; English improved; a version appeared in Prog.
Theor. Phy
The exact decomposition of gauge variables in lattice Yang-Mills theory
In this paper, we consider lattice versions of the decomposition of the Yang-
Mills field a la Cho-Faddeev-Niemi, which was extended by Kondo, Shinohara and
Murakami in the continuum formulation. For the SU(N) gauge group, we propose a
set of defining equations for specifying the decomposition of the gauge link
variable and solve them exactly without using the ansatz adopted in the
previous studies for SU(2) and SU(3). As a result, we obtain the general form
of the decomposition for SU(N) gauge link variables and confirm the previous
results obtained for SU(2) and SU(3).Comment: 16 page
Compact lattice formulation of Cho-Faddeev-Niemi decomposition: string tension from magnetic monopoles
In this paper we begin on a new lattice formulation of the non-linear change
of variables called the Cho--Faddeev--Niemi decomposition in SU(2) Yang-Mills
theory. This is a compact lattice formulation improving the non-compact lattice
formulation proposed in our previous paper. Based on this formulation, we
propose a new gauge-invariant definition of the magnetic monopole current which
guarantees the magnetic charge quantization and reproduces the conventional
magnetic-current density obtained in the Abelian projection based on the
DeGrand--Toussaint method. Finally, we demonstrate the magnetic monopole
dominance in the string tension in SU(2) Yang-Mills theory on a lattice. Our
formulation enables one to reproduce in the gauge-invariant way remarkable
results obtained so far only in the Maximally Abelian gauge.Comment: 14 pages, v2: minor corrections; v3: explanations added and improve
ppK- bound states from Skyrmions
The bound kaon approach to the strangeness in the Skyrme model is applied to
investigating the possibility of deeply bound states. We describe the
system as two-Skyrmion around which a kaon field fluctuates. Each
Skyrmion is rotated in the space of SU(2) collective coordinate. The rotational
motions are quantized to be projected onto the spin-singlet proton-proton
state. We derive the equation of motion for the kaon in the background field of
two Skyrmions at fixed positions. From the numerical solution of the equation
of motion, it is found that the energy of can be considerably small, and
that the distribution of shows molecular nature of the system.
For this deep binding, the Wess-Zumino-Witten term plays an important role. The
total energy of the system is estimated in the Born-Oppenheimer
approximation. The binding energy of the state is MeV.
The mean square radius of the subsystem is
fm.Comment: Oct 2007, 15 pages, 8 figures; added references, corrected typo
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