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 $\beta=4/g^2$, reaching five around $\beta=2.85$, 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 $20^4$). 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 $\beta = 2.6$. Both the Binder cumulant and the magnetization itself exhibit crossings in this region using lattices up to $20^4$, 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 $\beta_{\rm{adjoint}}$. 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