Effects of Improvement: f_π and m_q

We present a study of the effects of improvement on light-quark physics using the Fermilab formalism. The calculations were performed at three different lattice spacings, with the SW action and traditional Wilson action (both tadpole improved). We find that $O(a)$ effects for the decay constant $f_\pi$ and quark mass $m_q$ can be successfully removed using the tadpole-improved SW action in the light-quark regime.