Charged pion form factor betweenQ2=0.60and 2.45GeV2. I. Measurements of the cross section for the1H(e,e'π+)nreaction

Abstract

Cross sections for the reaction 1H(e,e'π+)n were measured in Hall C at Thomas Jefferson National Accelerator Facility (JLab) using the high-intensity Continuous Electron Beam Accelerator Facility (CEBAF) to determine the charged pion form factor. Data were taken for central four-momentum transfers ranging from Q2=0.60 to 2.45 GeV2 at an invariant mass of the virtual photon-nucleon system of W=1.95 and 2.22 GeV. The measured cross sections were separated into the four structure functions σL,σT,σLT, and σTT. The various parts of the experimental setup and the analysis steps are described in detail, including the calibrations and systematic studies, which were needed to obtain high-precision results. The different types of systematic uncertainties are also discussed. The results for the separated cross sections as a function of the Mandelstam variable t at the different values of Q2 are presented. Some global features of the data are discussed, and the data are compared with the results of some model calculations for the reaction 1H(e,e'π+)n.16 MoreReceived 11 July 2008DOI:https://doi.org/10.1103/PhysRevC.78.045202©2008 American Physical Society