Lattice2010

Session

Parallel 31: Vacuum structure and confinement

15 Jun 2010, 14:30

Villasimius, Sardinia

53. Lattice Index Theorem and Fractional Topological Charge

Roman Höllwieser (VUT)

15/06/2010, 14:30

Vacuum structure and confinement

We study topological properties of classical spherical center vortices from the low-lying eigenmodes of the Dirac operator, in both the overlap and asqtad formulations, fundamental and adjoint representation. In particular we address the puzzle raised in a previous work of our work group\ [Phys. Rev. D 77, 14515 (2008)], where we found a violation of the lattice index theorem with the overlap...

170. NSPT study of the three-loop lattice gluon propagator in Landau gauge

Christian Torrero (University of Regensburg)

15/06/2010, 14:50

Vacuum structure and confinement

By means of Numerical Stochastic Perturbation Theory (NSPT), we investigate the lattice gluon propagator up to the third loop in the limit of infinite volume and at vanishing lattice spacing. Based on known anomalous dimensions and a parametrization of both the hypercubic symmetry group H(4) and finite-size effects, we calculate the non-logarithmic contributions iteratively starting with...

189. Probing the Yang-Mills vacuum with adjoint zero-modes

Alfonso Sastre (IFT-UAM/CSIC)

15/06/2010, 15:10

Vacuum structure and confinement

We analyse in detail a filtering method proposed by Gonzalez-Arroyo and Kirchner to eliminate ultra-violat noise and probe the topological content of Monte-Carlo ensembles. The proposal is based on looking for the low lying eigen-modes of a super-symmetric operator constructed from a projection of the adjoint-Dirac operator. For classical configurations the density of these modes provides a...

233. The deconfinement transition in 2+1 dimensional SU(3) from twisted boundary conditions and self-duality

Nils Strodthoff (Institut fuer Kernphysik, TU Darmstadt)

15/06/2010, 15:30

Vacuum structure and confinement

We study the pure SU(3) lattice gauge theory in 2+1 dimensions using 't Hooft's twisted boundary conditions to force non-vanishing center flux through the finite box. In this way we measure the free energy of spacelike center vortices as an order parameter for the deconfinement transition. The transition is of second order and by the Svetitsky-Jaffe conjecture it falls into the universality...

234. Exploring center symmetry with electrically charged quarks

Sam R Edwards (Institut für Kernphysik, TU-Darmstadt)

15/06/2010, 15:50

Vacuum structure and confinement

In pure SU(N) gauge theory, the deconfinement phase transition is tied to the spontaneous breaking of center symmetry. The expectation value of the Polyakov jumps from zero to a finite value at T_c, which coincides with the suppression of spacelike center vortices. Center symmetry is lost, however, with the introduction of dynamical quarks, and this picture evaporates with it. Still, since...