The Double Spin Asymmetry for Exclusive $\pi^{+}$ Production

The eg1b run was conducted using CLAS (CEBAF Large Acceptance Spectrometer) at the Thomas Jefferson National Accelerator Facility (TJNAF) in 2000 by the CLAS collaboration. A 1.6 GeV - 5.6 GeV polarized electron beam and polarized nuclear targets (composed of NH$_{3}$ and ND$_{3}$) were used, allowing spin asymmetries to be measured. This analysis is of the double spin asymmetry $A_{||}$ in the exclusive production of positive pions from a polarized proton ($ep\rightarrow e\pi^{+}n$). The double spin asymmetry was measured as a function of the four kinematic variables $W$, $Q^{2}$, $\cos\theta ^{*}$ (the angle between the direction of the virtual photon and the produced pion), and $\phi^{*}$ (the angle between the lepton interaction plane and the hadron interaction plane). This asymmetry helps determine the spin structure of the resonances. A brief description of the experimental setup will be given, and preliminary results of the asymmetry as a function of $W$ will be shown.