Abstract

The interference term between s- and t-pole contributions to the p(e, e'pi+)n cross section is evaluated on the basis of the constituent quark model. It is shown that the contribution of baryon s-poles can be modeled by a nonlocal extension of the Kroll-Ruderman contact term. This contribution is in a destructive interference with the pion t-pole that is essential to improve the description of recent JLab data at the invariant mass W = 1.95 GeV. Some predictions are made for a new JLab measurement at higher values W = 2.1-2.3 GeV and Q(2) centered at 1.6 and 2.45 GeV2/c(2). (c) 2006 Elsevier B.V. All rights reserved.