arXiv subjects

Hideo Suganuma

Publications and source records attributed to Hideo Suganuma.

At least 145 records · Page 8Linked to original sources

arXiv1999

Dual Higgs Mechanism based on the Dual Gauge Formalism in the Lattice QCD

We study the dual Higgs mechanism induced by monopole condensation based on the dual gauge formalism in the maximally abelian (MA) gauge in the lattice QCD. To examine ``monopole condensation'' in QCD, we study the monopole part or the monopole-current system appearing in the MA gauge by extracting the dual gluon field $B_μ$. First, we investigate the inter-monopole potential using the dual Wilson loop in the lattice QCD simulation. In the monopole part in the MA gauge, the inter-monopole potential is found to be flat, and can be fitted as the Yukawa potential in the infrared region. From more detailed analysis of the inter-monopole potential considering the monopole size, we estimate the effective dual-gluon mass $m_B \simeq 0.5$GeV and the effective monopole size $R_{^{_{\rm M}}} \simeq 0.2$fm. Second, we study the dual gluon propagator $G^D_{μν}(x-y) \equiv < B_μ(x) B_ν(y) >_{\rm MA}$ in the MA gauge, and find that $G^D_{μμ}$ behaves as the massive vector-boson propagator with $m_B \simeq 0.4$ GeV in the infrared region. The effective-mass acquirement of the dual gluon field $B_μ$ at the long distance can be regarded as the lattice QCD evidence of ``infrared monopole condensation'' in the MA gauge.

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arXiv1999

Flux-Tube Ring and Glueball Properties in the Dual Ginzburg-Landau Theory

An intuitive approach to the glueball using the flux-tube ring solution in the dual Ginzburg-Landau theory is presented. The description of the flux-tube ring as the relativistic closed string with the effective string tension enables us to write the hamiltonian of the flux-tube ring using the Nambu-Goto action. Analyzing the Schrödinger equation, we discuss the mass spectrum and the wave function of the glueball. The lowest glueball state is found to have the mass $M_G \sim 1.6 GeV$ and the size $R_G \sim 0.5 fm$.

hep-ph↗

arXiv1999

Dual Wilson Loop and Infrared Monopole Condensation in Lattice QCD in the Maximally Abelian Gauge

Using the SU(2) lattice QCD, we formulate the dual Wilson loop and study the dual Higgs mechanism induced by monopole condensation in the maximally abelian (MA) gauge, where QCD is reduced into an abelian gauge theory including the electric current $j_μ$ and the monopole current $k_μ$. After the abelian projection in the MA gauge, the system can be separated into the photon part and the monopole part corresponding to the separation of $j_μ$ and $k_μ$, respectively. We study here the monopole part (the monopole-current system), which is responsible to the electric confinement. Owing to the absence of electric currents, the monopole part is naturally described using the dual gluon field $B_μ$ without the Dirac-string singularity. Defining the dual Wilson loop from the dual gluon $B_μ$, we find the perimeter law of the dual Wilson loop in the lattice QCD simulation. In the monopole part in the MA gauge, the inter-monopole potential is found to be flat, and can be fitted as the Yukawa potential in the infrared region after the subtraction of the artificial finite-size effect on the dual Wilson loop. From more detailed analysis of the inter-monopole potential considering the monopole size, we estimate the effective dual-gluon mass $m_B \simeq 0.5$GeV and the effective monopole size $R \simeq 0.2$fm. The effective mass of the dual gluon field at the long distance can be regarded as an evidence of ``infrared monopole condensation''.

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arXiv1998

Confinement Physics in Quantum Chromodynamics

We study the confinement physics in QCD in the maximally abelian (MA) gauge using the SU(2) lattice QCD, based on the dual-superconductor picture. In the MA gauge, off-diagonal gluon components are forced to be small, and the off-diagonal angle variable $χ_μ(s)$ tends to be random. Within the random-variable approximation for $χ_μ(s)$, we analytically prove the perimeter law of the off-diagonal gluon contribution to the Wilson loop in the MA gauge, which leads to abelian dominance on the string tension. To clarify the origin of abelian dominance for the long-range physics, we study the charged-gluon propagator in the MA gauge using the lattice QCD, and find that the effective mass $m_{ch} \simeq 0.9 {\rm GeV}$ of the charged gluon is induced by the MA gauge fixing. In the MA gauge, there appears the macroscopic network of the monopole world-line covering the whole system, which would be identified as monopole condensation at a large scale. To prove monopole condensation in the field-theoretical manner, we derive the inter-monopole potential from the dual Wilson loop in the monopole part of QCD, which carries the nonperturbative QCD aspects, in the MA gauge. The dual gluon mass is evaluated as $m_B \simeq $0.5GeV in the monopole part in the infrared region, which is the evidence of the dual Higgs mechanism by monopole condensation.

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arXiv1998

Intersection between Microscopic and Macroscopic Abelian Dominance in the Confinement Physics of QCD

We study abelian dominance for confinement in terms of the local gluon properties in the maximally abelian (MA) gauge, where the diagonal component of the gluon is maximized by the gauge transformation. We find microscopic abelian dominance on the link-variable for the whole region of $β$ in the lattice QCD in the MA gauge. The off-diagonal angle variable, which is not constrained by the MA-gauge fixing condition, tends to be random besides the residual gauge degrees of freedom. Within the random-variable approximation for the off-diagonal angle variable, we analytically prove that off-diagonal gluon contribution $W^{\rm off}$ to the Wilson loop obeys the perimeter law in the MA gauge. The perimeter-law behavior of $W^{\rm off}$ is also confirmed using the lattice QCD simulation. This indicates macroscopic abelian dominance for the string tension.

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arXiv1998

Monopoles and Gluon Fields in QCD in the Maximally Abelian Gauge

We study monopoles and gluon fields in QCD in the maximally abelian (MA) gauge in the context of the dual superconductor picture for confinement. In the abelian gauge, unit-charge magnetic monopoles appear, but multi-charge monopoles do not in general cases. The appearance of the monopole is studied using the gauge-connection formalism in relation to the SU($N_c$) singular gauge transformation. The relevant role of off-diagonal gluons is found for the appearance of monopoles in the abelian gauge in QCD. We study the gluon-field properties around the monopole in the MA gauge in terms of the action density using the lattice QCD. The monopole provides infinitely large field fluctuations in the abelian sector. In the MA gauge, off-diagonal gluons are strongly suppressed but largely remain around the monopole, which indicates the effective size and the structure of monopoles. We find the large cancellation between the abelian part and the off-diagonal part of the action density around the monopole in the MA gauge. Owing to this cancellation, the monopole can appear in QCD without large cost of the QCD action. Finally, we generalize the framework of the abelian projection, {\it i.e.} the extraction of the abelian gauge manifold from QCD, by introducing the `gluonic Higgs field' $\vec ϕ_D[A_μ(x)]$ defined from the ${\rm SU}(N_c)$ covariant derivative $\hat D_μ$. By way of $\vec ϕ_D[A_μ(x)]$, the maximally abelian projection can be performed in the gauge-covariant manner without the notion of gauge fixing in principle.

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arXiv1998

Semi-analytical Proof of Abelian Dominance on Confinement in the Maximally Abelian Gauge

We study abelian dominance for confinement in terms of the local gluon properties in the maximally abelian (MA) gauge in a semi-analytical manner with the help of the lattice QCD. The global Weyl symmetry persistently remains as the relic of SU($N_c$) in the MA gauge, and provides the ambiguity on the electric and magnetic charges. We derive the criterion on the SU($N_c$)-gauge invariance in terms of the residual symmetry in the abelian gauge. In the lattice QCD, we find microscopic abelian dominance on the link variable for the whole region of $β$ in the MA gauge. The off-diagonal angle variable, which is not constrained by the MA-gauge fixing condition, tends to be random besides the residual gauge degrees of freedom. Within the random-variable approximation for the off-diagonal angle variable, we prove that off-diagonal gluon contribution to the Wilson loop obeys the perimeter law in the MA gauge, and show exact abelian dominance for the string tension, although small deviation is brought by the finite size effect of the Wilson loop in the actual lattice QCD simulation.

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arXiv1998

Dual Higgs Theory for Color Confinement

We study theoretical bases of the dual Higgs theory for confinement physics in QCD in terms of monopoles and the gluon configuration in the maximally abelian (MA) gauge. Abelian dominance for the confinement force can be analytically proved by regarding the off-diagonal angle variable as a random variable in the lattice formalism. In the long-distance scale, the contribution of off-diagonal gluons to the Wilson loop cancels each other and exhibits a perimeter law behavior, which leads to exact abelian dominance on the string tension if the finite size effect of the Wilson loop is removed. We investigate the appearance of the monopole in the QCD vacuum, considering the role of off-diagonal gluons. The monopole carries a large fluctuation of the gluon field and provides a large abelian action in abelian projected QCD. Due to the partial cancellation between the abelian part and the off-diagonal part of the QCD action, the monopole can appear in QCD without large cost of the QCD action. The off-diagonal gluon is necessary for existence of the monopole at the short-distance scale. We study monopole condensation, which is the requirement of the dual Higgs theory, by comparing the QCD vacuum with the monopole-current system. We find that ``entropy'' of monopole-current dominates than its ``energy'', and the monopole seems to be condensed at the infrared scale in the QCD vacuum.

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arXiv1998

Instantons and Monopoles in the Nonperturbative QCD

We study the confinement physics in QCD in the maximally abelian (MA) gauge using the SU(2) lattice QCD. To clarify the origin of abelian dominance for the long-range physics, we study the charged-gluon propagator in the lattice QCD, and find that the effective mass $m_{ch} \simeq 0.9 {\rm GeV}$ of the charged gluon is induced by the MA gauge fixing. In the MA gauge, there appears the global network of the monopole world-line covering the whole system, which would be identified as monopole condensation at a large scale. To prove monopole condensation, we apply the dual gauge formalism to the monopole part, and derive the inter-monopole potential from the dual Wilson loop in the MA gauge. In the monopole part, which carries the nonperturbative aspects of QCD, the dual gluon mass is evaluated as $m_B \simeq $0.5GeV, which is the evidence of the dual Higgs mechanism by monopole condensation. As for the monopole structure, the large fluctuation of off-diagonal gluons remains around the monopole in the MA gauge, and large cancellation occurs between the diagonal and off-diagonal action densities to keep the total QCD action finite. The charged-gluon rich region around the QCD-monopole would provide the effective monopole size as the critical scale of the abelian projected QCD. Instantons are expected to appear in the charged-gluon rich region around the monopole world-line in the MA gauge, which leads to the local correlation between monopoles and instantons.

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arXiv1998

H-dibaryon matter in the Skyrme model on a hypersphere

We study the properties of H-dibaryon matter through the SO(3) Skyrmion solution on a three-dimensional hypersphere $S^3$. As the density increases, the swelling of H-dibaryon is found. Above a critical density, the system becomes uniform in terms of the baryon density. In this uniform phase, the critical order parameter is largely reduced, which can be interpreted as the chiral symmetry restoration. From the comparison with the $SO(2) \times SO(2)$ solution, the SO(3) soliton is found to be the true ground state for high density system with $R \leq 0.64$ fm in the B=2 sector with $N_f=3$.

hep-ph↗

arXiv1998

Hadronic flux-tubes in the Dual Ginzburg-Landau Theory

We study the flux-tube solution in the dual Ginzburg-Landau (DGL) theory and apply it to the understanding of quark-gluon-plasma (QGP) formation in the ultra-relativistic heavy ion collision as the multi-flux-tube system. It is concluded that the annihilation process of two flux-tubes can contribute to the QGP formation with the energy deposition $\sim 4 GeV/fm^3$. Furthermore, we study the glueball as the flux-tube ring by combining the DGL theory with the string theory, and find the mass and the size as $\sim 1.2 GeV$ and $\sim 0.22 fm$, respectively.

hep-ph↗

arXiv1998

Behavior of monopole trajectories in the instanton and anti-instanton system at finite temperature

We study the connection between monopoles and instantons in the Polyakov-like gauge, and the behavior of the monopole trajectories generated by instantons at finite temperature. The monopole trajectories become long and complicated at the zero-temperature which can be regarded as monopole condensation. On the other hand, they tend to become simple at finite temperature. It is suggested that such a change is related to the confinement-deconfinement phase transition.

hep-ph↗

arXiv1998

Monopoles in QCD

Based on the dual Higgs picture for confinement, we study monopole properties in the maximally abelian (MA) gauge using the lattice QCD. The monopole carries a large fluctuation of the gluon field and provides a large abelian action in abelian projected QCD (AP-QCD). We find large cancellation between abelian part and off-diagonal part of the action density around the monopole, which ensures the appearance of monopoles. The monopole in the MA gauge can be regarded as the collective mode of the large gluon fluctuation concentrated into the abelian sector, and would be relevant degrees of freedom for confinement in AP-QCD.

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arXiv1997

Gluon Propagator in Maximally Abelian Gauge and Abelian Dominance for Long-Range Interaction

We study the gluon propagator in the MA gauge with the lattice QCD Monte Carlo simulation. The simulation is performed using the heat-bath algorithm on the SU(2) lattice with $12^3 \times 24$ and $β= 2.3, 2.35$. The propagator of the off-diagonal charged gluon behaves as the massive gauge boson and provides the short-range interaction, while the diagonal gluon propagates long distance. This is the origin of the abelian dominance in the long-range physics.

hep-lat↗

arXiv1997

Dual Wilson Loop and Inter-Monopole Potential in Lattice QCD

We study the dual Wilson loop and the inter-monopole potential(the static potential between the color magnetic monopoles) in the maximally abelian gauge to clarify the dual Higgs mechanism induced by monopole condensation. There is no (color-)electric current in the monopole part, which includes the essence of the nonperturbative QCD, and hence the system can be described by the dual gauge field $B_μ$ without the singularity like the Dirac string. We find that the dual Wilson loop seems to obey the perimeter law, and the inter-monopole potential becomes Yukawa-type in the infrared region. From the inter-monopole potential, we estimate the dual gluon mass $m_B$ and the effective size $R$ of the monopole: $m_B \simeq 0.5$GeV, $R \simeq 0.35$fm.

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arXiv1997

Instanton, Monopole Condensation and Confinement

The confinement mechanism in the nonperturbative QCD is studied in terms of topological excitation as QCD-monopoles and instantons. In the 't Hooft abelian gauge, QCD is reduced into an abelian gauge theory with monopoles, and the QCD vacuum can be regarded as the dual superconductor with monopole condensation, which leads to the dual Higgs mechanism. The monopole-current theory extracted from QCD is found to have essential features of confinement. We find also close relation between monopoles and instantons using the lattice QCD. In this framework, the lowest $0^{++}$ glueball (1.5 $\sim$ 1.7GeV) can be identified as the QCD-monopole or the dual Higgs particle.

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arXiv1997

The Role of Monopoles for Color Confinement

We study the role of the monopole for color confinement by using the monopole current system. For the self-energy of the monopole current less than ln$(2d-1)$, long and complicated monopole world-lines appear and the Wilson loop obeys the area law, and therefore the monopole current system almost reproduces essential features of confinement properties in the long-distance physics. In the short-distance physics, however, the monopole-current theory would become nonlocal due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism.

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arXiv1997

Confinement Properties in the Multi-Instanton System

We investigate the confinement properties in the multi-instanton system, where the size distribution is assumed to be $ ρ^{-5} $ for the large instanton size $ ρ$. We find that the instanton vacuum gives the area law behavior of the Wilson loop, which indicates existence of the linear confining potential. In the multi-instanton system, the string tension increases monotonously with the instanton density, and takes the standard value $ σ\simeq 1 GeV/fm $ for the density $ (N/V)^{1/4} = 200 MeV $. Thus, instantons directly relate to color confinement properties.

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