Non-perturbative determination of the axial current normalization constant in 0( a) improved lattice QCD
A finite-size technique is employed to compute the normalization constant ZA of the isovector axial current in lattice QCD. The calculation is carried out in the quenched approximation for values of the bare gauge coupling g0 ranging from 0 to 1. In the lattice action and the lattice expression for the axial current we include the counterterms required for O( a) improvement, withaffe non-perturbatively determined coefficients. With little additional work the normalization constant ZV of the improved isospin current is also obtained.