3,278 research outputs found
Chiral Extension of Lattice Gauge Theory
Two approaches are presented to coupling explicit Goldstone modes to
flavors of massless quarks preserving exact chiral
symmetry on the lattice. The first approach is a generalization a chiral
extension to QCD (aka XQCD) proposed by Brower, Shen and Tan consistent with
the Ginsparg-Wilson relation. The second approach based on the Callan,Coleman,
Wess and Zumino coset construction has a real determinant atzero quark axial
coupling, .Comment: Lattice2003 3 pages, 1 figur
Hybrid Monte Carlo Simulation of Graphene on the Hexagonal Lattice
We present a method for direct hybrid Monte Carlo simulation of graphene on
the hexagonal lattice. We compare the results of the simulation with exact
results for a unit hexagonal cell system, where the Hamiltonian can be solved
analytically.Comment: 5 pages, 4 figure
The Chiral Extension of Lattice QCD
The chiral extension of Quantum Chromodynamics (XQCD) adds to the standard
lattice action explicit pseudoscalar meson fields for the chiral condensates.
With this action, it is feasible to do simulations at the chiral limit with
zero mass Goldstone modes. We review the arguments for why this is expected to
be in the same universality class as the traditional action. We present
preliminary results on convergence of XQCD for naive fermions and on the
methodology for introducing counter terms to restore chiral symmetry for Wilson
fermions.Comment: 7 pages, LATTICE 94 talk by R. Brower: Latex file with 2 postscript
figures for encapsulatio
Simplicial Chiral Models
Principal chiral models on a d-1 dimensional simplex are introduced and
studied analytically in the large limit. The and
models are explicitly solved. Relationship with standard lattice models and
with few-matrix systems in the double scaling limit are discussed.Comment: 6 pages, PHYZZ
Magnetic Monopole Content of Hot Instantons
We study the Abelian projection of an instanton in as a
function of temperature (T) and non-trivial holonomic twist () of the
Polyakov loop at infinity. These parameters interpolate between the circular
monopole loop solution at T=0 and the static 't Hooft-Polyakov
monopole/anti-monopole pair at high temperature.Comment: 3 pages, LATTICE98(confine), LaTeX, PostScript figures include
The M\"obius Domain Wall Fermion Algorithm
We present a review of the properties of generalized domain wall Fermions,
based on a (real) M\"obius transformation on the Wilson overlap kernel,
discussing their algorithmic efficiency, the degree of explicit chiral
violations measured by the residual mass () and the Ward-Takahashi
identities. The M\"obius class interpolates between Shamir's domain wall
operator and Bori\c{c}i's domain wall implementation of Neuberger's overlap
operator without increasing the number of Dirac applications per conjugate
gradient iteration. A new scaling parameter () reduces chiral
violations at finite fifth dimension () but yields exactly the same
overlap action in the limit . Through the use of 4d
Red/Black preconditioning and optimal tuning for the scaling , we
show that chiral symmetry violations are typically reduced by an order of
magnitude at fixed . At large we argue that the observed scaling for
for Shamir is replaced by for the
properly tuned M\"obius algorithm with Comment: 59 pages, 11 figure
Saturation and Confinement: Analyticity, Unitarity and AdS/CFT Correspondence
In expansion, analyticity and crossing lead to crossing even and odd
() vacuum exchanges at high-energy, the {\em Pomeron} and the {\em
Odderon}. We discuss how, using {\em String/Gauge duality}, these can be
identified with a reggeized {\em Graviton} and the anti-symmetric {\em
Kalb-Ramond fields} in background. With confinement, these Regge
singularities interpolate with glueball states. We also discuss unitarization
based on eikonal sum in .Comment: more references added. presented at ISMD 2008, 15-20 Sept. 200
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