Related papers: Perfect and Quasi-Perfect Lattice Actions
We describe a number of aspects in our attempt to construct an approximately perfect lattice action for QCD. Free quarks are made optimally local on the whole renormalized trajectory and their couplings are then truncated by imposing…
In recent years, reallistic unquenched QCD simulations have been carried out with various lattice actions. In this report, I explain the progress in theory and algorithms and some of the physics results.
A quantum perfect lattice action in four dimensions can be derived analytically as a renormalized trajectory when we perform a block spin transformation of monopole currents in a simple but non-trivial case of quadratic monopole…
There exist lattice actions which give cut--off independent physical predictions even on coarse grained lattices. Rotation symmetry is restored, the spectrum becomes exact and, in addition, the classical equations have scale invariant…
We show how to include a chemical potential \mu in perfect lattice actions. It turns out that the standard procedure of multiplying the quark fields \Psi, \bar\Psi at Euclidean time t by \exp(\pm \mu t), respectively, is perfect. As an…
We construct an optimally local perfect lattice action for free scalars of arbitrary mass, and truncate its couplings to a unit hypercube. Spectral and thermodynamic properties of this ``hypercube scalar'' are drastically improved compared…
We give a prescription how to include a chemical potential \mu into a general lattice action. This inclusion does not cause any lattice artifacts. Hence its application to an improved - or even perfect - action at \mu =0 yields an improved…
We describe a systematic approach to generating approximate actions for the lattice simulation of QCD. Three different tuning conditions are defined to match approximate with true actions, and it is shown that these three conditions become…
A block-spin transformation on the dual lattice leads us to an almost perfect lattice action for monopoles and strings in QCD. The perfect operator for a static quark potential is fixed when we compare the above action with the perfect…
Some topics from recent progresses in lattice QCD are reviewed.
In this review we discuss the general features of maximally twisted lattice QCD. In particular, we illustrate how automatic O(a) improvement can be achieved and how it is possible to set up a lattice regularization scheme where the problem…
We construct a perfect lattice action for staggered fermions by blocking from the continuum. The locality, spectrum and pressure of such perfect staggered fermions are discussed. We also derive a consistent fixed point action for free gauge…
We derive lattice actions for Yang-Mills quantum mechanics for models with $\cQ=4, 8$ and 16 supercharges which possess an exact supersymmetry at non-zero lattice spacing. These are obtained by dimensional reduction of twisted versions of…
The past few years have seen many interesting theoretical developments in lattice QCD. This talk (which is intended for non-experts) focuses on the problem of non-perturbative renormalization and the question of how precisely the continuum…
An overview of the Lattice technique for studies of the strong interaction is given. Recent results from the UKQCD lattice collaboration are presented. These concentrate on spectral quantities calculated using full (i.e. unquenched) QCD. A…
Recent Lattice QCD results relevant for Kaon, Charm and B Physics are summarized. There is general agreement among calculations using a wide range of different lattice actions. This bolsters confidence in the lattice results and in their…
We use perturbation theory to construct perfect lattice actions for fermions and gauge fields by blocking directly from the continuum. When one uses a renormalization group transformation that preserves chiral symmetry the resulting lattice…
Lattice actions and topological charges that are classically and quantum mechanically perfect (i.e. free of lattice artifacts) are constructed analytically for the quantum rotor. It is demonstrated that the Manton action is classically…
We discuss the possibility of representing supersymmetry exactly in a lattice discretized system. In particular, we construct a perfect supersymmetric action for the Wess-Zumino model.
A variety of lattice discretisations of continuum actions has been considered, usually requiring the correct classical continuum limit. Here we discuss "weird" lattice formulations without that property, namely lattice actions that are…