A lattice finite-size scaling study of spontaneous chiral symmetrybreaking in QCD

by Silvia Necco (University of Valencia and IFIC)

Thursday 5 Jul 2007, 14:00 → 15:00 Europe/Zurich

TH AMPHITHEATRE (CERN)

Lattice QCD can be adopted as powerful non-perturbative tool to match QCD with the chiral effective theory and extract low-energy constants from first principles. In particular I will present the computation of the chiral condensate using (quenched) Ginsparg-Wilson fermions. The matching is realized in the so-called epsilon regime and the low-energy constant is extracted through a finite-size scaling study. I will show that it is possible to construct observables which are free from mass-dependent ultraviolet divergences and which can be efficiently computed using variance-reduction techniques. I will then compare the mass, volume and topology dependence of the condensate with the predictions of the chiral effective theory and extract the corresponding low-energy constant.