We report measurements of the electroproduction reaction e + p --> e + pi+ + n for pions produced between 60 and 90° in the virtual-photon-proton center-of-mass system. The cross section is studied as a function of the center-of-mass energy, W, and the square of the virtual-photon mass, -Q^2, in the region 1.2 GeV <~ W <~ 3.0 GeV, 1.2 GeV^2 <~ Q^2 <~ 4.4 GeV^2. The data show a strong W dependence in accord with simple quark-model predictions but exhibit a Q^2 dependence which is difficult to explain in the context of such a model.
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