Exclusive meson electroproduction

Abstract

Jefferson Lab experiment E01-002 obtained data that can be used to determine the cross section of the process p(e; e0¼+)n at the invariant mass range of 1:3 GeV · W · 2:0 GeV (second and third resonance regions) and at a forward angular range of 0:6 · cos µcm · 1. These data have recently been used for resonance studies that have employed the ¼0 and ´ channels to study the lower mass states like ¢(1232) and the S11(1535). However, many of the higher mass isospin 1 2 resonances couple more strongly to the ¼+n channel. With data from E01-002, this dissertation presents the cross section obtained on this channel at an average Q2 value of 5.5 GeV2. This is the highest Q2 measurement of this exclusive process to date. The results are sensitive to high-mass resonances and diverge significantly from a recent theoretical model extrapolation of lower Q2 data.