19,979 research outputs found
Monopole Loop Distribution and Confinement in SU(2) Lattice Gauge Theory
The abelian-projected monopole loop distribution is extracted from maximal
abelian gauge simulations. The number of loops of a given length falls as a
power of the length nearly independent of lattice size. This power increases
with , reaching five around , beyond which loops any
finite fraction of the lattice size vanish in the infinite lattice limit,
suggesting the continuum theory lacks confinement.Comment: 6 pages Latex, 4 eps figures. Minor editing. Final version, to appear
in Physics Letters
Deconfinement from Action Restriction
The effect of restricting the plaquette to be greater than a certain cutoff
value is studied. The action considered is the standard Wilson action with the
addition of a plaquette restriction, which should not affect the continuum
limit of the theory. In this investigation, the strong coupling limit is also
taken. It is found that a deconfining phase transition occurs as the cutoff is
increased, on all lattices studied (up to ). The critical cutoff on the
infinite lattice appears to be around 0.55. For cutoffs above this, a fixed
point behavior is observed in the normalized fourth cumulant of the Polyakov
loop, suggesting the existence of a line of critical points corresponding to a
massless gluon phase, not unlike the situation in compact U(1). The Polyakov
loop susceptibility also appears to be diverging with lattice size at these
cutoffs. A strong finite volume behavior is observed in the pseudo-specific
heat. It is discussed whether these results could still be consistent with the
standard crossover picture which precludes the existence of a deconfining phase
transition on an infinite symmetric lattice.Comment: 4 pages latex, 6 ps figures, uses espcrc2.sty (included). Poster
presented at LATTICE96(topology
Particle velocity experiments in anorthosite and gabbro
Shock wave experiments were conducted in San Gabriel anorthosite and San Marcos gabbra 10 11 GPa using a 40 mm-borne propellant gun. Particle velocities were measured directly at several points in each target by means of electromagnetic gauges. Hugoniot states were calculated by determining shock-transit time from the gauge records. Sound speeds indicate a loss of shear strength upon sock compression for both rocks, with the strength loss persisting upon release to zero stress om the anorthosite. Stress-density release paths in the anorthosite indicate possible transformation of albite to jadeite + (quartz or coesite), with the amount of material transformed increasing as a function of shock stress. Electrical interferene effects in the gabbro precluded the determination of accurate release paths for the rock
Exploring Residual Gauge Symmetry Breaking
Simulations of pure-gauge SU(2) lattice gauge theory are performed in the
minimal Coulomb gauge. This leaves a residual or remnant gauge symmetry still
active which is global in three directions but still local in one. Using
averaged fourth-dimension pointing links as a spin-like order parameter, the
remnant symmetry appears to undergo spontaneous symmetry breaking at around
. Both the Binder cumulant and the magnetization itself exhibit
crossings in this region using lattices up to , and a susceptibility peak
is also observed. Finite size scaling indicates a weak first-order transition.
The symmetry breaking is also observed to take place in the fundamental-adjoint
plane, and is coincident with the strong first-order transition that exists
there at large . This provides confirmation that this
phase transition is a symmetry-breaking transition. A well-known theorem
concerning the instantaneous Coulomb potential has previously proven that a
transition where such a Coulomb-gauge remnant symmetry breaks is necessarily
deconfining.Comment: 7 pages, 4 figures (6 figure files), PoS style, Lattice 2006
Poster(Topology and Confinement
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