Precision Calculation of the Electromagnetic Radii of the Proton and Neutron from Lattice QCD.

We present lattice-QCD results for the electromagnetic form factors of the proton and neutron including both quark-connected and -disconnected contributions. The parametrization of the Q^{2} dependence of the form factors is combined with the extrapolation to the physical point. In this way, we determine the electric and magnetic radii and the magnetic moments of the proton and neutron.

Nucleon Sigma Terms with N_{f}=2+1 Flavors of O(a)-Improved Wilson Fermions.

We present a lattice-QCD based analysis of the nucleon sigma terms using gauge ensembles with N_{f}=2+1 flavors of O(a)-improved Wilson fermions, with a complete error budget concerning excited-state contaminations, the chiral interpolation as well as finite-size and lattice spacing effects. We compute the sigma terms determined directly from the matrix elements of the scalar currents. The chiral interpolation is based on SU(3) baryon chiral perturbation theory using the extended on-mass shell renormalization scheme.

Quark and Gluon Momentum Fractions in the Pion from N_{f}=2+1+1 Lattice QCD.

We perform the first full decomposition of the pion momentum into its gluon and quark contributions. We employ an ensemble generated by the Extended Twisted Mass Collaboration with N_{f}=2+1+1 Wilson twisted mass clover fermions at maximal twist tuned to reproduce the physical pion mass. We present our results in the MS[over ¯] scheme at 2 GeV.

Excited states in nucleon structure calculations.

Excited state contributions represent a formidable challenge for hadron structure calculations in lattice QCD. For physical systems that exhibit an exponential signal-to-noise problem they often hinder the extraction of ground state matrix elements, introducing a major source of systematic error in lattice calculations of such quantities. The development of methods to treat the contribution of excited states and the current status of related lattice studies are reviewed with focus on nucleon structure calculations that are notoriously affected by excited state contamination.

Strange Electromagnetic Form Factors of the Nucleon with N_{f}=2+1 O(a)-Improved Wilson Fermions.

We present results for the strange contribution to the electromagnetic form factors of the nucleon computed on the coordinated lattice simulation ensembles with N_{f}=2+1 flavors of O(a)-improved Wilson fermions and an O(a)-improved vector current. Several source-sink separations are investigated in order to estimate the excited-state contamination. We calculate the form factors on six ensembles with lattice spacings in the range of a=0.