Higher Twist Distribution Amplitudes of Vector Mesons in QCD: Formalism   and Twist Three Distributions
  We present a systematic study of twist three light-cone distribution amplitudes of vector mesons in QCD, which is based on conformal expansion and takes into account meson and quark mass corrections. A complete set of distribution amplitudes is constructed for rho, omega, K* and phi mesons, which satisfies all (exact) equations of motion and constraints from conformal expansion. Nonperturbative input parameters are calculated from QCD sum rules, including an update of SU(3) breaking corrections in the leading twist distributions. 
Patricia Ball, V.M. Braun, Y. Koike and K. Tanaka