One-loop renormalisation of quark bilinears for overlap fermions with improved gauge actions QCDSF Collaboration

We compute lattice renormalisation constants of local bilinear quark operators for overlap fermions and improved gauge actions. Among the actions we consider are the symanzik, luescher-weisz, iwasaki and DBW2 gauge actions. The results are given for a variety of #rho# parameters. We show how to apply mean field (tadpole) improvement to overlap fermions. The question, what is a good gauge action, is discussed from the perturbative point of view. Finally, we show analytically that the gauge dependent part of the self-energy and the amputated green functions are independent of the lattice fermion representation, using either wilson or overlap fermions. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(04-021) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Perturbative renormalisation of the second moment of generalised parton distributions

We calculate the non-forward quark matrix elements of operators with two covariant derivatives needed for the renormalisation of the second moment of generalised parton distributions in one-loop lattice perturbation theory using Wilson fermions. For some representations of the hypercubic group commonly used in simulations we determine the sets of all possible mixing operators. For those representations the one-loop mixing matrices of renormalisation factors are found. Due to non-vanishing contributions of operators with external ordinary derivatives the number of contributing operators increases compared to forward matrix elements. (orig.)SIGLEAvailable from TIB Hannover / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Generalized parton distributions and transversity from full lattice QCD

We present here the latest results from the QCDSF collaboration for moments of generalized parton distributions and transversity in two-flavour QCD, including a preliminary analysis of the pion mass dependence. (orig.)SIGLEAvailable from TIB Hannover: RA 2999(05-009) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

A lattice determination of g_A and left angle x right angle from overlap fermions

We present results for the nucleon's axial charge g_A and the first moment left angle x right angle of the unpolarized parton distribution function from a simulation of quenched overlap fermions. (orig.)SIGLEAvailable from TIB Hannover: RA2999(04-191) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman