Lattice QCD in the chiral regime: low mode averaging technique and topology conserving actions

por Silvia Necco (IFIC)

viernes 16 dic. 2005 12:00 → 13:00 Europe/Madrid

Sala Seminarios IFIC (Edf. Institutos de Investigación)

lattice QCD is a powerful tool to investigate non-perturbative features of strong interactions. In particular, by using the Neuberger formulation for fermions, chiral symmetry is preserved on the lattice and the chiral regime of QCD can be explored. In recent years, lattice simulations in the so-called epsilon-regime allowed to compute the Low Energy constants of the effective Chiral Lagrangian. In this talk I will present some useful technique which can be adopted in this contest: first I will discuss the low-mode averaging method, which is able to reduce large fluctuations in correlation functions due to low-mode eigenvalues of the Dirac operator. In particular, I will show an application to baryon two-point functions. Secondly I will present a particular formulation of the lattice SU(3) gauge action which suppresses topological transitions and could hence be profitable in the epsilon-regime, where predictions for observables in a fixed topological sector are avalaible.