TOWARDS A UNIFIED PICTURE OF CONSTITUENT AND CURRENT QUARKS

Using a simple picture of the constituent quark as a composite system of point-like partons, we construct the parton distributions by a conv olution between constituent quark momentum distributions and constitue nt quark structure functions. We evaluate the latter at a low hadronic scale with updated phenomenological information, and we build the mom entum distributions using well-known quark models. The resulting parto n distributions and structure functions are evolved to the experimenta l scale and good agreement with the available DIS data is achieved. Wh en compared with a similar calculation using non-composite constituent quarks, the accord with experiment of the present calculation becomes impressive. We therefore conclude that DIS data are consistent with a low energy scenario dominated by composite, mainly non-relativistic c onstituents of the nucleon. (C) 1998 Elsevier Science B.V.