Measuring the interface tension when the electroweak phase transition becomes weak

We measure the interface tension near the phase transition endpoint of the 3d SU(2)-Higgs model. The tunnel correlation length method is used and compared to other approaches. A modified scaling behaviour for the mass gap as function of the transverse area is proposed. (orig.)Available from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

3-dimensional lattice studies of the electroweak phase transition at M_H_i_g_g_s#approx# 70 GeV

We study the electroweak phase transition by lattice simulations of an effective 3-dimensional theory, for a Higgs mass of about 70 GeV. Exploiting, among others, a variant of the equal weight criterion of phase equilibrium, we obtain transition temperature, latent heat and surface tension, and compare with M_H#approx#35 GeV. In the broken phase masses and Higgs condensates are compared to perturbation theory. For the symmetric phase, bound state masses and the static force are determined. (orig.)28 refs.SIGLEAvailable from TIB Hannover: RA 2999(113) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Polarized and unpolarized nucleon structure functions from lattice QCD

We report on a high statistics quenched lattice QCD calculation of the deep-inelastic structure functions F_1, F_2, g_1 and g_2 of the proton and neutron. The theoretical basis for the calculation is the operator product expansion. We consider the moments of the leading twist operators up to spin four. Using Wilson fermions the calculation is done for three values of K, and we perform the extrapolation to the chiral limit. The renormalization constants, which lead us from lattice to continuum operators, are calculated in perturbation theory to one loop order. (orig.)32 refs.Available from TIB Hannover: RA 2999(95-128) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Non-perturbative versus perturbative renormalization of lattice operators

Our objective is to compute the moments of the deep-inelastic structure functions of the nucleon on the lattice. A major source of uncertainty is the renormalization of the lattice operators that enter the calculation. In this talk we compare the renormalization constants of the most relevant twist-two bilinear quark operators which we have computed non-perturbatively and perturbatively to one loop order. Furthermore, we discuss the use of tadpole improved perturbation theory. (orig.)6 refs.SIGLEAvailable from TIB Hannover: RA 2999(95-179) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Lattice computation of structure functions

Recent lattice calculations of hadron structure functions are described. (orig.)21 refs.Available from TIB Hannover: RA 2999(96-151) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Perturbative renormalization of lattice bilinear quark operators

Our aim is to compute the lower moments of the unpolarized and polarized deep-inelastic structure functions of the nucleon on the lattice. The theoretical basis of the calculation is the operator product expansion. To construct operators with the appropriate continuum behavior out of the bare lattice operators one must absorb the effects of momentum scales far greater than any physical scale into a renormalization of the operators. In this work we compute the renormalization constants of all bilinear quark operators of leading twist and spin up to four. The calculation is done for Wilson fermions and in the quenched approximation where dynamical quark loops are neglected. (orig.)21 refs.Available from TIB Hannover: RA 2999(96-034) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

A lattice evaluation of the deep-inelastic structure functions of the nucleon

The lower moments of the unpolarized and polarized deep-inelastic structure functions of the nucleon are calculated on the lattice. The calculation is done with Wilson fermions and for three values of the hopping parameter #kappa#, so that we can perform the extrapolation of the chiral limit. Particular emphasis is put on the renormalization of lattice operators. The renormalization constants, which lead us from lattice to continuum operators, are computed perturbatively to one loop order as well as non-perturbatively. (orig.)14 refs.SIGLEAvailable from TIB Hannover: RA 2999(95-178) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Towards a lattice calculation of the nucleon structure functions

We have initiated a programme to compute the lower moments of the unpolarised and polarised deep inelastic structure functions of the nucleon in the quenched approxiation. We review our progress to date. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(94-227) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Recent results on the nucleon structure functions from lattice QCD

We report on recent results of a high statistics lattice calculation of the unpolarized and polarized structure functions of the nucleon. (orig.)9 refs.Available from TIB Hannover: RA 2999(95-203) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Lattice operators for moments of the structure functions and their transformation under the hypercubic group

For lattice operators that are relevant to the calculation of moments of nucleon structure functions we investigate the transformation properties under the hypercubic group. We give explicit bases of irreducible subspaces for tensors of rank #<=#4. (orig.)7 refs.Available from TIB Hannover: RA 299(96-031) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman