No abstract

The cross section for quasielastic 12C(e, e'p) scattering has been measured at momentum transfer Q~ = 1, 3, 5 , and 6.8 (Gev/c) ' [I] have suggested that, at sufficiently high momentum transfer, the final (and initial) state interactions of hadrons with the nuclear medium should be reduced, leading to the phenomenon termed "color transparency." Although the arguments were originally formulated within the context of perturbative QCD (high momentum transfer approximation of the strong interaction), recent work [2] indicates that this phenomenon occurs in a wide variety of model calculations with nonperturbative reaction mechanisms.The requirements for the existence of color transparency have been discussed recently [2] and are briefly summarized here. First, high momentum transfer scattering should take place via selection of amplitudes in the initial and final state hadrons characterized by a small transverse size (much smaller than the hadron radius). Secondly, this small object should be "color neutral" outside of this small radius in order not to radiate gluons (which would lead to inelasticity). The object, being small and color neutral, would then have reduced inter-003 1 -9007/94/72( 1 3)/1986(4)$06.00

We have performed absolute measurements of the differential cross section for elastic e-p scattering in the range of momentum transfer from Q2 = 2.9 to 31.3 (GeV/c)2. Combined statistical and systematic uncertainties in the cross section measurements ranged from 3% at low Q2 to 19% at high Q2. These data have been used to extract the proton magnetic form factor GG(Q2). The results show a smooth decrease of Q"GG with momentum transfer above Q2 = 10 (GeV/c)2. These results are compared with recent predictions of perturbative QCD.

Cross swtions for threshold electron scattering from the proton have been measured in the missing-mass squared region M2 < W2 < 2 (GeV) 2 and the four-momentum transfer squared region 6< Q2 <30 (GeV/c)2. Scaling of the extracted values of the structure function F2 = VW2 is examined in the variables z,~, and W2. The best scaling is found for the quantity Q6F2, which is found to be linearly proportional to (W2-W~~), where~th = M + Mm.

No abstract