A Model for the Generalized Parton Distribution of the Pion
  We calculate the off-forward structure function of the pion within a simple model where the size of the pion is accounted for using a momentum cut-off. Twist-two and twist-three generalized parton distributions are extracted. Relations between twist-three and twist-two contributions are obtained, the origin of which is not kinematical as they differ from those arising from the Wandzura-Wilczek approximation. 
P.Stassart, F.Bissey, J.R.Cudell, J.Cugnon, J.P. Lansberg