Mass spectrum and decay constants in the continuum limit

We present first results for light hadron masses, quark masses and decay constants in the continuum limit using O(a) improved fermions at three different values of the gauge coupling #beta#. (orig.)Available from TIB Hannover: RA 2999(98-153) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Improved quenched QCD on large lattices - first results

Continuing our investigations of quenched QCD with improved fermions we have started simulations for lattice size 32"3 x 64 at #beta# = 6.2. We present first results for light hadron masses at #kappa# = 0.13520, 0.13540, and 0.13555. Moreover we compare our initial experiences on the T3E with those for APE/Quadrics systems. (orig.)Available from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Is there a Landau Pole problem in QED?

We investigate a lattice version of QED by numerical simulations. For the renormalized charge and mass we find results which are consistent with the renormalized charge vanishing in the continuum limit. A detailed study of the relation between bare and renormalized quantities reveals that the Landau pole lies in a region of parameter space which is made inaccessible by spontaneous chiral symmetry breaking. (orig.)10 refs.SIGLEAvailable from TIB Hannover: RA 2999(97-252) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Resolution of the Landau pole problem in QED

We present new numerical results for the renormalized mass and coupling in non-compact lattice QED with staggered fermions. Implications for the continuum limit and the role of the Landau pole are discussed. (orig.)4 refs.SIGLEAvailable from TIB Hannover: RA 2999(97-258) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Seeking the equation of state of non-compact lattice QED

We perform a high statistics calculation of the equation of state for non-compact QED on large lattices. The calculation extends to fermionic correlation lengths of #approx#8, and it is combined with a finite size scaling analysis of the lattice data. (orig.)23 refs.Available from TIB Hannover: RA 2999(96-084) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Spectroscopy and renormalisation group flow of a lattice Nambu-Jona-Lasinio model

We investigate a lattice Nambu-Jona-Lasinio model both by the Monte Carlo method and Schwinger-Dyson equations. A comparison allows the discussion of finite size effects and the extrapolation to infinite volume. We pay special attention to the identification of particles and resonances. This enables us to discuss renormalisation group flows in the neighbourhood of the critical coupling where the chiral symmetry breaking phase transition takes place. In no region of the bare parameter space do we find renormalisability for the model. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(93-195) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

The present status of non-compact lattice QED

We give a 1993 update of non-compact lattice QED, in particular the chiral condensate, finite size effects and meson mass ratios. We compare descriptions of the phase transition. Our previous conclusions remain valid. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(93-178) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Baryonic flux in quenched and two-flavor dynamical QCD

We study the distribution of color electric flux of the three-quark system in quenched and full QCD (with N_f=2 flavors of dynamical quarks) at zero and finite temperature. To reduce ultra-violet fluctuations, the calculations are done in the Abelian projected theory fixed to the maximally Abelian gauge. In the confined phase we find clear evidence for a Y-shape flux tube surrounded and formed by the solenoidal monopole current, in accordance with the dual superconductor picture of confinement. In the deconfined, high temperature phase monopoles cease to condense, and the distribution of the color electric field becomes Coulomb-like. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(04-004) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman