We review the status of an ongoing long-term lattice investigation of the spectrum and structure of tetraquark candidates. We focus on the light scalar meson a0(980). First steps regarding the study of a possibly existing ccc̄c̄ tetraquark are also outlined.

We discuss W boson production at HERA including NLO QCD corrections. A detailed comparison with previous work is presented.

Supersymmetry predicts that gauge couplings are equal to the corresponding gauginosfermion-fermion Yukawa couplings. This prediction can be tested for the QCD sector of the MSSM by studying the processes e+e− → squark+antisquark+gluon and e+e− → squark+antiquark+gluino at a future linear collider. We present results for these processes at next-to-leading order in αs in the framework of the MSSM...

The partial widths are determined for stop decays to top quarks and gluinos, and gluino decays to stop particles and top quarks (depending on the masses of the particles involved). The widths are calculated including one-loop SUSYQCD corrections. The radiative corrections for these strong-interaction decays are compared with the SUSY-QCD corrections for electroweak stop decays to quarks and neu...

We present recent results on the first moments of parton distributions using gauge configurations generated with two degenerate flavors of light twisted mass quarks with pion mass fixed approximately to its physical value. We also present a first study of the vector parton distribution function using a twisted mass ensemble at pion mass of 373 MeV.

The evaluation of the NNLO QCD corrections to the production of a scalar and a pseudo-scalar Higgs boson is described. The evaluation of the NNLO QCD corrections to the production of a scalar and a pseudo-scalar Higgs boson is described.