Inelastice−pScattering Data and a New Parton Model

Abstract

We elaborate on the application of the parton concepts to inelastic lepton-nucleon scattering. We propose a series of sum rules connecting the structure function $\nu W_2(\nu ,Q^2)$ and the properties of the partons. In particular, a sum rule is derived relating the structure function of the neutron and the proton which depends only on the charge distribution of the partons. We then attempt to generalize the quark-parton model of Bjorken and Paschos (BP) so as to fit the data on inelastic $e-p$ scattering which are presently available. We find that we are unable to fit the data with this model. A new model is therefore developed in which the partons are not identified with quarks, and the minimum number of partons is four (whereas in the BP model it is three). It is found that this model gives an excellent fit to the data in the approximation that the scale invariance is true. It is pointed out that the minimum number of partons plays an important role in parton models. Our fits also show that the mean square charge per parton is very small, which rules out any reasonable possibility of associating individual quarks with partons.