Activities

The Theoretical High Energy Physics Division is performing phenomenological research, with special emphasis on the strong interaction (QCD), including multiparticle production and signals for "new physics" in high energy colliders (in particular at the upcoming Large Hadron Collider, LHC), as well as studies of the strong and weak interaction at lower energies. The topics of research include:

Studies of the event structure in high energy reactions, e+e- annihilation, lepton-proton and hadron-hadron collisions. This is a very wide field, which includes many separate phenomena such as saturation effects at small x, multiple jet events, the structure of the "underlying event", and diffraction.
Studies of resummation schemes and initial- and final-state perturbative QCD radiation in the dipole and the parton-shower approaches.
Matching of such radiation to fixed-order matrix-element calculations, including effects of loop corrections, and study of the resulting radiation patterns in association with gauge boson production in hadron collisions.
Studies of new physics within and beyond the standard model, including perturbative and nonperturbative QCD effects in top events, Higgs searches, and so on.
Particle correlations due to Bose-Einstein or Fermi-Dirac effects and fractal structures.
Soft hadronization effects, further development of the Lund model for quark and gluon jets, and colour interconnection effects in e+e- and in the underlying event in hadronic collisions.
Modeling of heavy-ion collisions, including various collective effects.
Development and support of event generators, PYTHIA, ARIADNE, ThePEG and LDCMC. These have found widespread use in the experimental high-energy-physics community, as indispensable tools for comparing theoretical ideas and experimental data, to understand the underlying strong interaction dynamics and to estimate backgrounds for new physics signals.
Chiral Perturbation Theory and related aspects, including connections to lattice gauge theory.
Study of Kaon and Eta Decays, meson-meson-scattering.
Study of non-perturbative aspects of the operator evolution of operators relevant for non-leptonic processes, including modeling of the intermediate energy domain; examples are the Delta I = ½ rule; Hadronic contributions to muon g-2.
CP violation phenomenology.
Determination of Quark Masses and CKM matrix elements.
Modeling a nonperturbative Higgs sector.
Active participation in various workshops on the physics program at current and future accelerators, such as HERA, LHC, DAPHNE, and e+e- linear colliders.

Positions

PhD positions

Activities

Positions

Computer Programs