Longitudinal electroproduction of charged pions from 1H, 2H, and 3He

Charged ion electroproduction from 1H, 2H, and 3He was measured. Data were taken for Q2=0.4 (GeV/c)2 at kinematics corresponding to the negative enhancement region and the positive enhancement region of the pion excess distribution. The experiment was carried out in Hall C using electron beam energies that ranged from 0.845 GeV to 3.245 GeV. The results show a clear suppression of the longitudinal strength at low k, and at high k are consistent with estimates derived from pion-excess calculations.