15011565
Gauge invariant 'monopoles' and color confinement mechanism
The dual Meissner effect is described and numerically observed in a gauge-invariant way in lattice Monte-Carlo simulations of pure SU(2) QCD. A gauge-invariant monopole-like quantity on the lattice is defined by a gauge-invariant Abelian-like field strength. The Abelian-like field strength is expressed in terms of a unit-vector in color space which is constructed by a non-Abelian field strength itself. It is just equal to the absolute value of the corresponding non-Abelian field strength except for the sign. In this note we show the theoretical background and most numerical results will be published in a separate report \cite{Suzuki:2005lat052} in this conference.
118116252
Gauge invariance of the dual Meissner effect in QCD
The dual Meissner effect is described and numerically observed in a gauge-invariant way in lattice Monte-Carlo simulations of pure SU(2) QCD. 
A gauge-invariant Abelian-like field strength is defined in terms of a unit-vector in color space which is constructed by a non-Abelian field strength itself. A gauge-invariant monopole-like quantity is defined by a violation of the Bianchi identity with respect to the Abelian-like field strength. The squeezing of the non-Abelian electric field $\sqrt{\sum_a(E^a_i)^2}$ between a pair of static quark and anti-quark occurs due to the solenoidal current coming from the gauge-invariant monopole-like quantity. An equation similar to the dual London equation is confirmed approximately in the long-range region.
6402063
Modified block BiCGSTAB for lattice QCD
Abstract We present results for application of block BiCGSTAB algorithm modified by the QR decomposition and the SAP preconditioner to the Wilson–Dirac equation with multiple right-hand sides in lattice QCD on 32 3 × 64 and 64 4 lattices at almost physical quark masses. The QR decomposition improves convergence behaviors in the block BiCGSTAB algorithm suppressing deviation between true residual and recursive one. The SAP preconditioner applied to the domain-decomposed lattice helps us minimize communication overhead. We find remarkable cost reduction thanks to cache tuning and reduction of number of iterations.