Inelastic electron-nucleon scattering

It is assumed that the process is dominated by one-photon exchange, shown in Fig. 15.4 but direct tests of this are not as complete as in the elastic case. 

One can test for the importance of two-photon exchange by comparing cross-sections using positrons and electrons as projectiles. It is intuitively easy to see why two-photon exchange will lead to a difference between the positron and electron cross-sections. Symbolically, one has 

The interference term changes sign under e+ — e. The same argument holds for In Fig. 15.5 the ratio a ix )/(r n ) is plotted vs 

Within errors the ratio is certainly compatible with the value 1. 

For large values of one in any case expects weak interaction effects to alter the one-photon behaviour, but for the present we shall proceed on the assumption that one-photon exchange is adequate. 

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Drees,J. Deep Inelastic Electron-Nucleon Scattering (Vol. 60)... 

A typical process, deep inelastic electron scattering on a nucleon, i.e. 

In Section 15.6 we introduced the formalism necessary for studying deep inelastic scattering using polarized electron or muon beams on polarized nucleon targets. Here we briefly present the parton model predictions for the structure functions Gi,2 and consider what may be learnt from the experiments with polarized beams and targets. 

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