Nucleon structure functions from a chiral soliton in the infinite momentumframe

We study the frame dependence of nucleon structure functions obtained withi n a chiral soliton model for the nucleon. Employing light cone coordinates and introducing collective coordinates together with their conjugate moment a, translational invariance of the solitonic quark fields (which describe t he nucleon as a localized object) is restored. This formulation allows us t o perform a Lorentz boost to the infinite momentum frame of the nucleon. Th e major result is that the Lorentz contraction associated with this boost c auses the leading twist contribution to the structure functions to properly vanish when the Bjorken variable x exceeds unity. Furthermore we demonstra te that for structure functions calculated in the valence quark approximati on to the Nambu-Jona-Lasinio chiral soliton model the Lorentz contraction a lso has significant effects on the structure functions for moderate values of the Bjorken variable x.