STRUCTURE FUNCTIONS OF PSEUDOSCALAR MESONS IN THE SU(3) NJL MODEL

We compute the structure functions of the pion, kaon and eta mesons us ing a SU(3) version of the NJL model with scalar and pseudoscalar coup lings. By considering the absorptive part of the forward Compton scatt ering amplitude, the regularization can be treated without ambiguities and gauge invariance is preserved at every stage of the calculation. Using Pauli-Villars regularization, the structure functions scale and have proper normalization in the Bjorken limit. In the chiral limit, t he simple result q(x) = (q) over bar(x) = theta(x)theta(1 - x) is obta ined for the structure functions. The results are evolved to higher mo mentum using the Altarelli-Parisi equations for three flavours, and go od agreement with the experimental data for the pion structure functio n found.