Learn More
Gunnar S. Bali, Norbert Eicker, Thomas Lippert, Hartmut Neff, Boris Orth, Klaus Schilling, Thorsten Struckmann and Jochen Viehoff Department of Physics & Astronomy, The University of Glasgow, Glasgow G12 8QQ, Scotland Fachbereich Physik, Bergische Universität Wuppertal, D-42097 Wuppertal, Germany von Neumann Institute for Computing, c/o Research Center(More)
In order to compute physical quantities in lattice quantum chromodynamics huge systems of linear equations have to be solved. The availability of eecient parallel Krylov subspace solvers plays a vital role in the solution of these systems. We present a detailed analysis of the performance of the stabilized biconjugate gradient (BiCGStab) algorithm with(More)
We present evidence for disconnected contributions to the σπN term and the flavor singlet axial coupling g 0 A of the proton on full QCD configurations, which are obtained by means of improved stochastic estimator techniques. Furthermore we discuss results from the fermionic determination of the topological charge of the QCD vacuum (in the spirit of the(More)
Critical Dynamics of the Hybrid Monte Carlo Algorithm SESAM + TχL-Collaboration: Th. Lippertb∗, G. Bali, N. Eicker, L. Giusti, U. Glässner, S. Güsken, H. Hoeber, G. Martinelli, F. Rapuano, G. Ritzenhöfer, K. Schilling, A. Spitz, and J. Viehoff Physics Department, Humboldt University, Berlin, Germany HLRZ, c/o Jülich Research Center and DESY, Hamburg,(More)
The investigation of light sea-quark effects in lattice QCD with dynamical Wilson fermions requires both larger physical volumes and finer lattice resolutions than achieved previously. As high-end supercomputers like the 512-node APE Tower provide the compute power to perform a major step towards the chiral limit (TχL), we have launched a feasibility study(More)
Critical Dynamics of the Hybrid Monte Carlo Algorithm SESAM + TχL-Collaboration: Th. Lippert, G. Bali, N. Eicker, L. Giusti, U. Glässner, S. Güsken, H. Hoeber, G. Martinelli, F. Rapuano, G. Ritzenhöfer, K. Schilling, A. Spitz, and J. Viehoff Physics Department, Humboldt University, Berlin, Germany HLRZ, c/o Jülich Research Center and DESY, Hamburg,(More)
We present results for the bb̄ spectrum obtained using an O(Mbv )-correct non-relativistic lattice QCD action. Propagators are evaluated on SESAM’s three sets of dynamical gauge configurations generated with two flavours of Wilson fermions at β = 5.6. Compared to a quenched simulation at equivalent lattice spacing we find better agreement of our dynamical(More)
Figure 1. Connected (a) and disconnected (b) diagrams contribute to the flavor singlet axial coupling G1A of the proton (jμ = q̄γμγ5q). The SESAM collaboration has analyzed 200 16 × 32 gauge configurations at each of their four quark masses corresponding to mπ/mρ = 0.833...0.686. The configurations have been generated previously in the standard Wilson(More)
Flavour symmetric hadronic states are of particular importance for the understanding of nonperturbative aspects of quantum chromodynamics (QCD). In fact they are expected to reveal important insight into the topological vacuum structure induced by gluonic self interactions, as borne out in the famous Witten-Veneziano formula 1 that relates the flavour(More)
Disconnected diagrams are expected to be sensitive to the inclusion of dynamical fermions. We present a feasibility study for the observation of such effects on the nucleonic matrix elements of the axial vector current, using SESAM full QCD vacuum configurations with Wilson fermions on 16 × 32 lattices, at β = 5.6. Starting from the standard methods(More)