arXiv subjects

Hideo Suganuma

Publications and source records attributed to Hideo Suganuma.

At least 163 records · Page 9Linked to original sources

arXiv1997

The Critical Scale of the Dual Superconductor Picture of QCD

The nonperturbative phenomena of QCD like color confinement is well described through the dual superconductor picture in the Maximally Abelian (MA) gauge. In this gauge, monopoles appear as important degrees of freedom composed by nonabelian gauge fields. We investigate the peculiar size $R_c$ of the monopole in the MA gauge, considering the theoretical similarity between spinglass and the MA gauge fixing. As for the properties at larger scale than the monopole size $R_c$, the system can be described by the dual superconductor theory with local abelian fields. At shorter distances than $R_c$, such a dual Higgs theory should be treated as a non-local field theory, and therefore one must take another framework like the perturbative QCD. Thus, the monopole size gives a critical scale on the change of the theoretical structure of QCD.

hep-lat↗

arXiv1997

Monopole Current Dynamics and Color Confinement

Color confinement can be understood by the dual Higgs theory, where monopole condensation leads to the exclusion of the electric flux from the QCD vacuum. We study the role of the monopole for color confinement by investigating the monopole current system. When the self-energy of the monopole current is small enough, long and complicated monopole world-lines appear, which is a signal of monopole condensation. In the dense monopole system, the Wilson loop obeys the area-law, and the string tension and the monopole density have similar behavior as the function of the self-energy, which seems that monopole condensation leads to color confinement. On the long-distance physics, the monopole current system almost reproduces essential features of confinement properties in lattice QCD. In the short-distance physics, however, the monopole-current theory would become nonlocal and complicated due to the monopole size effect. This monopole size would provide a critical scale of QCD in terms of the dual Higgs mechanism.

hep-lat↗

arXiv1996

Finite Temperature SD Equation for Chiral Symmetry Restoration in Dual Ginzburg-Landau Theory

We study the chiral phase transition at $T\neq 0$ in the dual Ginzburg-Landau theory using the Schwinger-Dyson (SD) equation. In order to solve the SD equation at $T\neq 0$, we provide a new ansatz for the quark self-energy in the imaginary-time formalism. The recovery of the chiral symmetry is found at $T_{_{C}}\sim 100 MeV$ with realistic parameters, which are set by reproducing the values of the string tension $\sqrtσ\simeq 0.44 GeV$ and the chiral condensate $< {\bar q}q > \simeq -(250 MeV}^{3}$ at $T=0$.

hep-ph↗

arXiv1996

Distribution of Instanton and Monopole Clustering

We study the relation between the instanton distribution and the monopole loop length in the SU(2) gauge theory with the abelian gauge fixing. We measure the monopole current from the multi-instanton ensemble on the $16^4$ lattice using the maximally abelian gauge. When the instanton density is dilute, there appear only small monopole loops. On the other hand, in the dense case, there appears one very long monopole loop, which is responsible for the confinement property, in each gauge configuration. We find a clear monopole clustering in the histogram of the monopole loop length from 240 gauge configurations.

hep-lat↗

arXiv1996

Instanton, Monopole and Confinement

We study the correlation between instantons and QCD-monopoles both in the lattice gauge theory and in the multi-instanton system using the maximally abelian gauge. First, we find the existence of an almost linear correlation between the total length of monopole trajectories and the total number of pseudoparticles (instantons and anti-instantons) in the $16^{3}\times4$ SU(2) lattice. Second, we study the features of QCD-monopole in the SU(2) multi-instanton vacuum on the $16^{4}$ lattice as a random ensemble of pseudoparticles. A signal of monopole condensation is found as the clustering of monopole trajectories, when the topological pseudoparticles is sufficiently dense.

hep-lat↗

arXiv1996

Clustering of Monopoles in the Instanton Vacuum

We generate a random instanton vacuum with various densities and size distributions. We perform numerically the maximally abelian gauge fixing of these configurations in order to find monopole trajectories induced by instantons. We find that instanton-induced monopole loops form enormous clusters occupying the whole physical volume, provided instantons are sufficiently dense. It indicates that confinement might be caused by instantons.

hep-lat↗

arXiv1996

QCD Phase Transition at high Temperature in Cosmology

The cosmological QCD phase transition is studied in terms of the color confinement at finite temperature using the dual Higgs theory of QCD. The confinement force is largely reduced at high temperature, which leads to the swelling of hadrons. We derive analytical formulae for the surface tension and the boundary thickness of the mixed phase from the effective potential at $T_c$. We predict a large reduction of the glueball mass near $T_c$. We investigate also the process of the hadron-bubble formation in the early Universe.

hep-ph↗

arXiv1996

Dual Higgs Mechanism and Nonperturbative QCD

We study the dual Higgs mechanism for the nonperturbative QCD. We point out two kind of the ``see-saw'' relations between electric and magnetic sectors. Owing to the Dirac condition $eg=4π$, the dual Ginzburg-Landau theory has the asymptotic freedom nature on the gauge coupling constant $e$, where the ``walking coupling constant'' is predicted for $e$ in the infrared region. We study also QCD-monopoles and instantons, which are two relevant topological objects in QCD. Strong correlations between the QCD-monopole trajectory and the topological charge are found both in the continuum theory and in the lattice gauge theory.

hep-ph↗

arXiv1996

Recent Progress in Nonperturbative QCD Theory and Insight on Cosmological Phase Transition

The QCD phase transition at finite temperature is studied with the dual Ginzburg-Landau theory, which is the QCD effective theory based on the dual Higgs mechanism by QCD-monopole condensation. At high temperature, the confinement force is largely reduced by thermal effects, which leads to the swelling of hadrons. Simple formulae for the surface tension and the thickness of the phase boundary are derived from the shape of the effective potential at the critical temperature. We investigate also the process of the hadron-bubble formation in the early Universe.

hep-ph↗

arXiv1996

Role of Dual Higgs Mechanism in Chiral Phase Transition at Finite Temperature

The chiral phase transition at finite temperature is studied by using the Schwinger-Dyson equation in the dual Ginzburg-Landau theory, in which the dual Higgs mechanism plays an essential role on both the color confinement and the spontaneous chiral-symmetry breaking. At zero temperature, the quark condensate is strongly correlated with the string tension, which is generated by QCD-monopole condensation, as $\langle {\bar q}q \rangle^{1/3} \stackrel{\propto}{\scriptstyle \sim} \sqrtσ$. In order to solve the finite-temperature Schwinger-Dyson equation numerically, we provide a new ansatz for the quark self-energy in the imaginary-time formalism. The recovery of the chiral symmetry is found at high temperature; $T_{_{C}}\sim 100{\rm MeV}$ with realistic parameters. We find also a strong correlation between the critical temperature $T_{_{C}}$ of the chiral symmetry restoration and the strength of the string tension.

hep-ph↗

arXiv1996

Monopole Dominance for Nonperturbative QCD

Monopole dominance for the nonperturbative features in QCD is studied both in the continuum and the lattice gauge theories. First, we study the dynamical chiral-symmetry breaking (D$χ$SB) in the dual Higgs theory using the effective potential formalism. We find that the main driving force for D$χ$SB is brought from the confinement part in the nonperturbative gluon propagator rather than the short-range part, which means monopole dominance for D$χ$SB. Second, the correlation between instantons and QCD-monopoles is studied. In the Polyakov-like gauge, where $A_4(x)$ is diagonalized, the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Finally, using the SU(2) lattice gauge theory with $16^4$ and $16^3 \times 4$, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) sectors, respectively. Instantons and anti-instantons only exist in the monopole sector both in the maximally abelian gauge and in the Polyakov gauge, which means monopole dominance for the topological charge.

hep-ph↗

arXiv1996

Chiral Symmetry Breaking in the Dual Ginzburg-Landau Theory

Confinement and chiral symmetry breaking are the most fundamental phenomena in Quark Nuclear Physics, where hadrons and nuclei are described in terms of quarks and gluons. The dual Ginzburg-Landau (DGL) theory, which contains monopole fields as the most essential degrees of freedom and their condensation in the vacuum, is modeled to describe quark confinement in strong connection with QCD. We then demonstrate that the DGL theory is able to describe the spontaneous break down of the chiral symmetry.

hep-ph↗

arXiv1995

Evidence of Strong Correlation between Instanton and QCD-monopole on SU(2) Lattice

The correlation between instantons and QCD-monopoles is studied both in the lattice gauge theory and in the continuum theory. An analytical study in the Polyakov-like gauge, where $A_4(x)$ is diagonalized, shows that the QCD-monopole trajectory penetrates the center of each instanton, and becomes complicated in the multi-instanton system. Using the SU(2) lattice with $16^4$, the instanton number is measured in the singular (monopole-dominating) and regular (photon-dominating) parts, respectively. The monopole dominance for the topological charge is found both in the maximally abelian gauge and in the Polyakov gauge.

hep-lat↗

arXiv1995

Chiral Symmetry Restoration at Finite Temperature in the Dual Ginzburg-Landau Theory

We study the relation between QCD-monopole condensation and dynamical chiral-symmetry breaking in the dual Ginzburg-Landau Theory, which realizes the color confinement due to the dual Meissner effect. Solving the Schwinger-Dyson equation at finite temperature numerically, we find the chiral symmetry is restored at high temperature. The critical temperature of the chiral symmetry restoration is strongly correlated with the string tension.

hep-ph↗

arXiv1995

Dual Ginzburg-Landau Theory for Quark Confinement and Dynamical Chiral-Symmetry Breaking

Nonperturbative features of QCD are studied using the dual Ginzburg-Landau (DGL) theory with QCD-monopoles. The linear quark potential appears in the QCD-monopole condensed vacuum. We find that QCD-monopole condensation plays an essential role to the dynamical chiral-symmetry breaking. We also investigate the QCD phase transition at finite temperature in the DGL theory.

hep-ph↗

arXiv1995

QCD Phase Transition at Finite Temperature in the Dual Ginzburg-Landau Theory

We study the pure-gauge QCD phase transition at finite temperatures in the dual Ginzburg-Landau theory, an effective theory of QCD based on the dual Higgs mechanism. We formulate the effective potential at various temperatures by introducing the quadratic source term, which is a new useful method to obtain the effective potential in the negative-curvature region. Thermal effects reduce the QCD-monopole condensate and bring a first-order deconfinement phase transition. We find a large reduction of the self-interaction among QCD-monopoles and the glueball masses near the critical temperature by considering the temperature dependence of the self-interaction. We also calculate the string tension at finite temperatures.

hep-ph↗

arXiv1995

Dual Higgs Mechanism for Quarks in Hadrons

We study nonperturbative features of QCD using the dual Ginzburg-Landau (DGL) theory, where the color confinement is realized through the dual Higgs mechanism brought by QCD-monopole condensation. The linear confinement potential appears in the QCD-monopole condensed vacuum. We study the infrared screening effect to the confinement potential by the light-quark pair creation, and derive a compact formula for the screened quark potential. We study the dynamical chiral-symmetry breaking (D$χ$SB) in the DGL theory by solving the Schwinger-Dyson equation. QCD-monopole condensation plays an essential role to D$χ$SB. The QCD phase transition at finite temperature is studied using the effective potential formalism in the DGL theory. We find the reduction of QCD-monopole condensation and the string tension at high temperatures. The surface tension is calculated using the effective potential at the critical temperature. The DGL theory predicts a large mass reduction of glueballs near the critical temperature. We apply the DGL theory to the quark-gluon-plasma (QGP) physics in the ultrarelativistic heavy-ion collisions. We propose a new scenario of the QGP formation via the annihilation of color-electric flux tubes based on the attractive force between them.

hep-ph↗

arXiv1994

Dynamical Chiral-Symmetry Breaking in the Dual Ginzburg-Landau Theory

We study the effect of QCD-monopole condensation on the dynamical chiral-symmetry breaking by using the dual Ginzburg-Landau theory of QCD. We formulate the Schwinger-Dyson equation and solve it numerically. The large enhancement is found for the chiral-symmetry breaking due to QCD-monopole condensation, which suggests the close relation between the color confinement and the chiral-symmetry breaking.

hep-ph↗