scholarly journals Monopoles of the Dirac type and color confinement in QCD

2022 ◽  
Vol 258 ◽  
pp. 02005
Author(s):  
Tsuneo Suzuki ◽  
Atsuki Hiraguchi ◽  
Katsuya Ishiguro
Keyword(s):  
String Tension ◽  
Polyakov Loop ◽  
Multilevel Method ◽  
Dirac Type ◽  
Color Confinement ◽  
Monte Carlo Studies ◽  
Gauge Fixing ◽  
Electric Flux ◽  
First Time ◽  
The Continuum

We present results of SU(3) Monte-Carlo studies of a new color confinement scheme proposed recently due to Abelian-like monopoles of the Dirac type corresponding in the continuum limit to violation of the non-Abelian Bianchi identities (VNABI). The simulations are done without any additional gauge-fixing smoothing the vacuum. We get for the first time, in pure SU(3) simulations, (1) the perfect Abelian dominance with respect to the static potentials on (12 ~ 16)4 at β = 5.6 − 5.8 using the multilevel method, (2) the monopole as well as Abelian dominances with respect to the static potentials by evaluating the Polyakov-loop correlators on 243 × 4 at β = 5.6. The Abelian photon part gives zero string tension. The new SU(3) as well as the previous SU(2) results are consistent with the new Abelian picture of color confinement that each one of eight colored electric flux is squeezed by the corresponding colored Abelian-like monopole of the Dirac type corresponding to VNABI.

scholarly journals Confinement-deconfinement transition in dense SU(2) QCD

2018 ◽  
Vol 175 ◽  
pp. 07009 ◽  
Author(s):  
V. G. Bornyakov ◽  
V. V. Braguta ◽  
E.-M. Ilgenfritz ◽  
A. Yu. Kotov ◽  
I. E. Kudrov ◽  
...  
Keyword(s):  
Lattice Spacing ◽  
Continuum Limit ◽  
Chemical Potential ◽  
String Tension ◽  
Baryon Density ◽  
Polyakov Loop ◽  
Zero Temperature ◽  
Gauge Action ◽  
The Continuum

In this report we study the properties of the dense SU(2) QCD. The lattice simulations are carried out with improved gauge action and smaller lattice spacing as compared to our previous work. This allowed us to approach closer to the continuum limit and reach larger densities without lattice artifacts. We measured string tension and Polyakov loop as functions of chemical potential and temperature. At suffciently large baryon density and zero temperature we observe confinement/deconfinement transition which manifests itself as a vanishing of the string tension and rising of the Polyakov loop.

scholarly journals MONOPOLES IN THE PLAQUETTE FORMULATION OF THE 3D SU(2) LATTICE GAUGE THEORY

2011 ◽  
Vol 26 (25) ◽  
pp. 1853-1867
Author(s):  
O. BORISENKO ◽  
S. VOLOSHYN ◽  
J. BOHÁČIK
Keyword(s):  
Lattice Gauge Theory ◽  
Semiclassical Approximation ◽  
Bianchi Identity ◽  
Three Dimensional ◽  
String Tension ◽  
Effective Theory ◽  
Type Model ◽  
Lattice Gauge ◽  
Electric Flux ◽  
The Continuum

Using a plaquette formulation for lattice gauge models we describe monopoles of the three-dimensional SU(2) theory which appear as configurations in the complete axial gauge and violate the continuum Bianchi identity. Furthermore, we derive a dual formulation for the Wilson loop in arbitrary representation and calculate the form of the interaction between generated electric flux and monopoles in the region of a weak coupling relevant for the continuum limit. The effective theory which controls the interaction is of the sine-Gordon type model. The string tension is calculated within the semiclassical approximation.

scholarly journals From Center-Vortex Ensembles to the Confining Flux Tube

Universe ◽  
2021 ◽  
Vol 7 (8) ◽  
pp. 253
Author(s):  
David R. Junior ◽  
Luis E. Oxman ◽  
Gustavo M. Simões
Keyword(s):  
Degrees Of Freedom ◽  
String Tension ◽  
Effective Field ◽  
Scaling Properties ◽  
Flux Tubes ◽  
Topological Solitons ◽  
Yang Mills ◽  
Center Vortex ◽  
Asymptotic Scaling ◽  
The Continuum

In this review, we discuss the present status of the description of confining flux tubes in SU(N) pure Yang–Mills theory in terms of ensembles of percolating center vortices. This is based on three main pillars: modeling in the continuum the ensemble components detected in the lattice, the derivation of effective field representations, and contrasting the associated properties with Monte Carlo lattice results. The integration of the present knowledge about these points is essential to get closer to a unified physical picture for confinement. Here, we shall emphasize the last advances, which point to the importance of including the non-oriented center-vortex component and non-Abelian degrees of freedom when modeling the center-vortex ensemble measure. These inputs are responsible for the emergence of topological solitons and the possibility of accommodating the asymptotic scaling properties of the confining string tension.

A Discussion on solar studies with special reference to space observations - A high resolution solar ultraviolet spectrum between 200 and 220 nm

1971 ◽  
Vol 270 (1202) ◽  
pp. 29-46 ◽  
Keyword(s):  
High Resolution ◽  
Solar Spectrum ◽  
Ultraviolet Spectrum ◽  
Absorption Feature ◽  
Intensity Analysis ◽  
Echelle Spectrograph ◽  
Broad Absorption ◽  
First Time ◽  
Solar Ultraviolet ◽  
The Continuum

A high resolution solar spectrum in the range 200 to 220 nm has been recorded with an echelle spectrograph launched in, a sun-pointing Skylark rocket. The data have been reduced and are presented as intensity-wavelength plots together with a wavelength list and proposed identifications. A broad absorption feature at 212.4 nm is assigned to a single source and an intensity analysis confirms this to be the non-resonance Sii line at 212.412 nm. The discontinuity in the continuum intensity near 208.7 nm is revealed with high resolution for the first time and is assigned to the photoionization edge of A11. An analysis shows that its intensity drop and wavelength position can only be explained by adjustments to the solar model in the region 0.001 < T 5000 < 0.2.

scholarly journals The first high-redshift changing-look quasars

2020 ◽  
Vol 498 (2) ◽  
pp. 2339-2353 ◽  
Author(s):  
Nicholas P Ross ◽  
Matthew J Graham ◽  
Giorgio Calderone ◽  
K E Saavik Ford ◽  
Barry McKernan ◽  
...  
Keyword(s):  
Emission Line ◽  
Rest Frame ◽  
Population Distribution ◽  
High Redshift ◽  
Baldwin Effect ◽  
Change Models ◽  
High Ionization ◽  
Rapid Changes ◽  
First Time ◽  
The Continuum

ABSTRACT We report on three redshift z &gt; 2 quasars with dramatic changes in their C iv emission lines, the first sample of changing-look quasars (CLQs) at high redshift. This is also the first time the changing-look behaviour has been seen in a high-ionization emission line. SDSS J1205+3422, J1638+2827, and J2228 + 2201 show interesting behaviour in their observed optical light curves, and subsequent spectroscopy shows significant changes in the C iv broad emission line, with both line collapse and emergence being displayed on rest-frame time-scales of ∼240–1640 d. These are rapid changes, especially when considering virial black hole mass estimates of MBH &gt; 109M⊙ for all three quasars. Continuum and emission line measurements from the three quasars show changes in the continuum-equivalent width plane with the CLQs seen to be on the edge of the full population distribution, and showing indications of an intrinsic Baldwin effect. We put these observations in context with recent state-change models, and note that even in their observed low-state, the C iv CLQs are generally above ∼5 per cent in Eddington luminosity.

scholarly journals SU(2) GLUON PROPAGATOR ON A COARSE ANISOTROPIC LATTICE

2000 ◽  
Vol 15 (37) ◽  
pp. 2245-2256 ◽  
Author(s):  
YING CHEN ◽  
BING HE ◽  
HE LIN ◽  
JI-MIN WU
Keyword(s):  
Continuum Limit ◽  
Anomalous Dimension ◽  
Gluon Propagator ◽  
Landau Gauge ◽  
Mass Scale ◽  
Gauge Fixing ◽  
Anisotropic Lattice ◽  
The Continuum

We calculated the SU(2) gluon propagator in Landau gauge on an anisotropic coarse lattice with the improved action. The standard and improved schemes are used to fix the gauge in this work. Even on the coarse lattice the lattice gluon propagator can be well described by a function of the continuous momentum. The effect of the improved gauge fixing scheme is found not to be apparent. Based on the Marenzoni's model, the mass scale and the anomalous dimension are extracted and can be reasonably extrapolated to the continuum limit with the values α~0.3 and M~600 MeV . We also extract the physical anisotropy ξ from the gluon propagator due to the explicit ξ dependence of the gluon propagator.

scholarly journals Relaxation methods applied to engineering problems. XI. Problems governed by the ‘quasi-plane-potential equation'

1945 ◽  
Vol 183 (994) ◽  
pp. 258-283 ◽  
Keyword(s):  
Finite Difference ◽  
Poisson Equation ◽  
String Tension ◽  
Finite Difference Approximation ◽  
Difference Approximation ◽  
Transverse Displacement ◽  
Relaxation Methods ◽  
Potential Equation ◽  
Engineering Problems ◽  
First Time

The ‘quasi-plane-potential equation’ ∂/∂x (X∂ψ/∂x) + ∂/∂y (x∂ψ/∂y) +Z = 0 is discussed in relation to problems where Z and x are known functions of x and y . It governs ( inter alia ) the small transverse displacement of a membrane in which the tension T ∝X, and its finite-difference approximation governs the small transverse displacements of nodal points of a net in which, similarly, the string tension T varies from node to node. (Equilibrium in the directions of x and y can be maintained, both in the membrane and in the net, by forces acting in those directions and accordingly having no effect on the transverse equilibrium.) The relaxational treatment, based on this mechanical (net) analogue, reduces when X is constant to the treatment developed, in earlier papers of this series, for problems governed by the ‘plane-harmonic’ (Poisson) equation, ∂ 2 ψ/∂x 2 + ∂ 2 ψ/∂ y 2 + Z = 0 Thus an opportunity is afforded for a review of various improvements which have been incorporated in the technique first propounded in Part III. In particular, this paper for the first time uses systematically the device of ‘graded nets’, i.e. nets of which the mesh-side a is smaller in some parts than in others.

scholarly journals Lattice gauge theory and gluon color-confinement in curved spacetime

2015 ◽  
Vol 30 (05) ◽  
pp. 1550020 ◽  
Author(s):  
Kristian Hauser Villegas ◽  
Jose Perico Esguerra
Keyword(s):  
Gauge Theory ◽  
Continuum Limit ◽  
Lattice Gauge Theory ◽  
Covariant Form ◽  
Curved Spacetime ◽  
Color Confinement ◽  
Lattice Gauge ◽  
Frw Metric ◽  
Generally Covariant ◽  
The Continuum

The lattice gauge theory (LGT) for curved spacetime is formulated. A discretized action is derived for both gluon and quark fields which reduces to the generally covariant form in the continuum limit. Using the Wilson action, it is shown analytically that for a general curved spacetime background, two propagating gluons are always color-confined. The fermion-doubling problem is discussed in the specific case of Friedman–Robertson–Walker (FRW) metric. Last, we discussed possible future numerical implementation of lattice QCD in curved spacetime.

scholarly journals Hamiltonian Approach to QCD in Coulomb Gauge: A Survey of Recent Results

2018 ◽  
Vol 2018 ◽  
pp. 1-21 ◽  
Author(s):  
H. Reinhardt ◽  
G. Burgio ◽  
D. Campagnari ◽  
E. Ebadati ◽  
J. Heffner ◽  
...  
Keyword(s):  
Spatial Dimension ◽  
String Tension ◽  
Quark Condensate ◽  
Coulomb Gauge ◽  
Hamiltonian Approach ◽  
Critical Temperatures ◽  
Yang Mills ◽  
Center Vortex ◽  
Gauge Fixing ◽  
Deconfinement Phase Transition

We report on recent results obtained within the Hamiltonian approach to QCD in Coulomb gauge. Furthermore this approach is compared to recent lattice data, which were obtained by an alternative gauge-fixing method and which show an improved agreement with the continuum results. By relating the Gribov confinement scenario to the center vortex picture of confinement, it is shown that the Coulomb string tension is tied to the spatial string tension. For the quark sector, a vacuum wave functional is used which explicitly contains the coupling of the quarks to the transverse gluons and which results in variational equations which are free of ultraviolet divergences. The variational approach is extended to finite temperatures by compactifying a spatial dimension. The effective potential of the Polyakov loop is evaluated from the zero-temperature variational solution. For pure Yang–Mills theory, the deconfinement phase transition is found to be second order for SU(2) and first order for SU(3), in agreement with the lattice results. The corresponding critical temperatures are found to be 275 MeV and 280 MeV, respectively. When quarks are included, the deconfinement transition turns into a crossover. From the dual and chiral quark condensate, one finds pseudocritical temperatures of 198 MeV and 170 MeV, respectively, for the deconfinement and chiral transition.

DETAILED STUDY OF THE FEW NUCLEON SYSTEMS AT JEFFERSON LAB

2003 ◽  
Vol 18 (02n06) ◽  
pp. 235-243
Author(s):  
◽  
ARUN SAHA
Keyword(s):  
Degrees Of Freedom ◽  
Bound State ◽  
Experimental Program ◽  
Body Structure ◽  
Relativistic Dynamics ◽  
Significant Strength ◽  
Continuum Region ◽  
Missing Momenta ◽  
First Time ◽  
The Continuum

In a new and detailed experimental program carried out at Jefferson Laboratory, the few nucleon systems has been studied via Electrodisintegration of Deuterium and the Helium nuclei. Interesting new results probing the high momentum structure have been studied via the (e,e'p) reaction using the two high resolution spectrometers in Hall A and various kinematic regions have been investigated. Detailed and precise information on the effective bound state momentum distributions have been measured for the first time up to missing momenta of 1 Gev/c in 3 He , exhibiting significant strength at these high momenta which the standard nuclear calculations fail to explain and could be an indication of the onset of non-nucleonic degrees of freedom. The continuum region in 3 He has also been investigated in great detail looking for nuclear correlations and quasi-deuteron strength. Response function separations have been carried out to extract details of the few body structure and relativistic dynamics. Measurements made so far on D and 4 He have focussed on specific kinematic regions and there are plans to extend them over kinematic ranges similar to the 3 He investigation.

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