  We investigate two-point correlation functions of left-handed currents
computed in quenched lattice QCD with the Neuberger-Dirac 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 epsilon-regimes. 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 p-regime we test volume and quark mass dependence of the
pseudoscalar decay constant and mass; in the epsilon-regime, 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 next-to-leading order effects.
