
We investigate twopoint correlation functions of lefthanded currents computed in quenched lattice QCD with the NeubergerDirac operator. We consider two lattice spacings a~0.09,0.12 fm and two different lattice extents L~ 1.5, 2.0 fm; quark masses span both the p and the epsilonregimes. We compare the results with the predictions of quenched chiral perturbation theory, with the purpose of testing to what extent the effective theory reproduces quenched QCD at low energy. In the pregime we test volume and quark mass dependence of the pseudoscalar decay constant and mass; in the epsilonregime, we investigate volume and topology dependence of the correlators. While the leading order behaviour predicted by the effective theory is very well reproduced by the lattice data in the range of parameters that we explored, our numerical data are not precise enough to test nexttoleading order effects.


Giusti, L. Hernández Gamazo, Pilar Necco, Silvia Pena Ruano, Carlos Wennekers, Jan Wittig, Hartmut 2008 Testing chiral effective theory with quenched lattice QCD Journal of High Energy Physics 2008 5 024 