Experimental Results on Scaling and the Neutron to Proton Cross Section Ratio in Deep Inelastic Electron Scattering

A review of present knowledge about the scaling of the neutron and proton structure functions and about the neutron to proton cross section ratio is presented, Empha- sis is placed on the results of a recent electron scattering experiment at SLAC from which neutron cross sections were extracted from deuterium data using an impulse approximation, The discovery of scaling' * in deep inelastic electron proton scat- tering resulted in the formulation of a number of theoretical models explaining the experimental data, Additional measurements2-' have estab- lished that the neutron exhibits scaling, but that the neutron cross sections are different from the proton cross sections, The study of the comparison of neutron and proton cross sections provide valuable tests of those nucleon structure models, In this presentation, we will review some of the experimental evidence for scaling in deep inelastic electron scattering. Emphasis will be placed on the results of a recent electron scattering experi- ment at S&X2 in which e-p and e-n cross sections were compared. A detailed discussion of the apparatus used in these electron scattering experiments can be found in Refs. 1-6, Briefly, an electron beam of energy E is incident on a liquid hydrogen or liquid deuterium target, Scattered electrons are detected by a magnetic spectrometer. The cross section