Measurement of the polarized structure function σL T' for p ( e→ , e' π+ ) n in the Δ ( 1232 ) resonance region

The polarized longitudinal-transverse structure function σ_{L T'} has been measured using the p ( e→ , e' π⁺ ) n reaction in the Δ ( 1232 ) resonance region at Q² =0.40 and 0.65 GeV² . No previous σ_{L T'} data exist for this reaction channel. The kinematically complete experiment was performed at the Jefferson Lab with the CEBAF large acceptance spectrometer using longitudinally polarized electrons at an energy of 1.515 GeV . A partial-wave analysis of the data shows generally better agreement with recent phenomenological models of pion electroproduction compared to the previously measured π⁰ p channel. A fit to both π⁰ p and π⁺ n channels using a unitary isobar model suggests the unitarized Born terms provide a consistent description of the nonresonant background. The t -channel pion pole term is important in the π⁰ p channel through a rescattering correction, which could be model dependent.