Nicht-perturbative Analyse von Effekten der starken Wechselwirkung, durch numerische Simulationen auf dem Gitter

• Applicant: Dr. Thomas Chiarappa
• Subject Area: Nuclear and Elementary Particle Physics, Quantum Mechanics, Relativity, Fields
• Term: from 2005 to 2007
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5442439

Our project is concerned with the investigation of non-perturbative aspects of Quantum ChromoDynamics (QCD), the field theory that is believed to describe strong interaction between elementary particles. In particular, we consider the theory regularised in a gauge invariant way on the lattice, where non-perturbative computations are feasible by means of Monte Carlo simulations. We will focus our attention on the theoretical evaluation of quantities relevant for the phenomenology of the Standard Model, such as Low Energy Constants of Chiral Perturbation Theory and matrix elements of the effective weak Hamiltonian operator, which are dominated by non-perturbative QCD contributions. We plan to simulate two different ultraviolet regularisations of the quark fields: chirally twisted Wilson fermions (twisted mass) and the overlap realization of chirally invariant Ginsparg - Wilson fermions (for small volumes). We also are going to improve algorithmic techniques relevant for: efficient computations with overlap fermions, initially still in the quenched approximation (i.e. without sea quark effects); unquenched simulations of fermions, in a first stage limited to the computationally less expensive formulation with chirally twisted Wilson fermions.

• DFG Programme: Research Fellowships
• International Connection: Italy