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In recent years the investigation of hadron structure using lattice techniques has attracted growing attention. The computation of several important quantities has become feasible. Furthermore, theoretical developments as well as progress in algorithms and an increase in computing resources have contributed to a significantly improved control of systematic errors. In this article we give an overview on the work that has been carried out in the framework of the Hadron Physics I3 (I3HP) network “Computational (lattice) hadron physics”. Here we will not restrict ourselves to spin physics but focus on results for nucleon spectrum and structure from the QCDSF collaboration. For a broader overview of developments in this field see, e.g., [1].

Abstract: In recent years the investigation of hadron structure using lattice techniques has attracted growing attention. The computation of several important quantities has become feasible. Furthermore, theoretical developments as well as progress in algorithms and an increase in computing resources have contributed to a significantly improved control of systematic errors. In this article we give an overview on the work that has been carried out in the framework of the Hadron Physics I3 (I3HP) network “Computational (lattice) hadron physics”. Here we will not restrict ourselves to spin physics but focus on results for nucleon spectrum and structure from the QCDSF collaboration. For a broader overview of developments in this field see, e.g., [1].

The scale parameter ΛMSis computed on the lattice in the quenched approximation and for Nf=2 flavors of light dynamical quarks. The dynamical calculation is done with non-perturbatively O(a) improved Wilson fermions. In the continuum limit we obtain ΛMSNf=0=243(1)(10) MeV and ΛMSNf=2=217(16)(11) MeV, respectively.

The topological susceptibility t2>/V is computed for theCP3-model appropriately discretized on simplicial lattices onT2 andS2, respectively. We concentrate on volumes 1?V/?2?100, ? being the correlation length measured onT2. Approximate scaling behaviour is found presumably not related to the continuum limit but rather to the occurence of dislocations. We observe finite-size effects which are fairly weak on the sphere, however.

We present new Monte Carlo results in non-compact lattice QED with staggered fermions down to m0= 0.005. This extends our previous investigations on the nature of the continuum limit of QED.