2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/213248In this paper we investigate the cutoff effects at tree-level of perturbation theory for three different lattice regularizations of fermions -- maximally twisted mass Wilson, overlap and Creutz fermions. We show that all three kinds of fermions exhibit the expected $O(a^2)$ scaling behaviour in the lattice spacing. Moreover, the size of these cutoff effects for the considered quantities i.e. the pseudoscalar correlation function $C_{PS}$, the mass $m_{PS}$ and the decay constant $f_{PS}$ is comparable for all of them.11 pages, 3 figures, presented at the 48. Cracow School of Theoretical Physics: Aspects of Duality, Zakopane, Poland, 13-22 June 2008High Energy Physics - Latticetext