ar X iv : h ep - p h / 99 10 38 2 v 1 1 8 O ct 1 99 9 On the Structure Functions of Mesons and Baryons in a Chiral Quark Model

This research summarizes work done by myself (Nucl.Phys.A641 (1998)461), or in collaboration with R. M. Davidson (Phys.Lett.B348(1995)163) and H. Weigel and L. Gamberg (Nucl.Phys.B560(1999)xx). I will discuss several topics related with the computation of structure functions in the quark model in general and its perturbative evolution. In particular, I address this topic in the Nambu–Jona–Lasinio model of hadrons, where the nucleon is constructed as a soliton. I show that the handling of the regularization procedure is crucial in order to obtain exact scaling in the Bjorken limit and fulfillment of sum rules. I also include some problems concerning the general validity of quark model calculations. 1. Reminder on Deep Inelastic Scattering Deep inelastic scattering (DIS) provides some of the most convincing evidence for the quark sub– structure [1] of hadrons. The main object of study which is experimentally measured is the so-called hadronic tensor, W ab μν(p, q; s) = 1 4π ∫