Testing Scaling and QCD with Muon Beams

Abstract

Scaling in muon-nucleon scattering suggests that nucleons are made of pointlike, non-interacting, light quarks. This scaling will go away at higher energies if the quarks are characterized by some non-zero size, a. Specifically, scaling for Q^2 ≾(3a)^(-2) will disappear completely for Q^2≈a^(-2). Alternatively, scaling may persist, at least to the accuracy that it is currently observed. Then we may ask if the observed violations are indeed those predicted by quark-gluon gauce theory (QCD). However, there are other, more dramatic predictions of QCD which will be easier to test. The most striking of these is the prediction of large transverse momenta of order Q^2/log4Q^2 (transverse to the nominal jet axes).