Exclusive π− electroproduction off the neutron in deuterium in the resonance region

Abstract

New results for the exclusive and quasifree cross sections off neutrons bound in deuterium γvn(p) → pπ − (p) are presented over a wide final state hadron angle range with a kinematic coverage of the invariant mass (W ) up to 1.825 GeV and the four-momentum transfer squared (Q 2 ) from 0.4 to 1.0 GeV 2 . The exclusive structure functions were extracted and their Legendre moments were obtained. Final-state-interaction contributions have been kinematically separated from the extracted quasifree cross sections off bound neutrons solely based on the analysis of the experimental data. These new results will serve as long-awaited input for phenomenological analyses to extract the Q 2 evolution of previously unavailable n → N * electroexcitation amplitudes and to improve state-of-the-art models of neutrino scattering off nuclei by augmenting the already available results from free protons.