rho-Meson wave functions from nonlocal light-cone operators with definite twist

We introduce chiral-even and chiral-odd meson wave functions as vacuum-to-m eson matrix elements of bilocal quark operators with well-defined (geometri c) twist. Thereby, we achieve a Lorentz invariant classification of these d istributions which differ from the conventional ones by explicitly taking i nto account the trace terms. The relations between conventional and new wav e functions are given. (C) 2001 Elsevier Science B.V. All rights reserved.