Rosenbluth Separation of the pion electroproduction cross section from Hydrogen, Deuterium, Carbon and Copper targets

Pion electroproduction data was collected from six targets, including hydrogen, deuterium, carbon and copper, in Jefferson Lab experiment E01-107. The primary motivation of this experiment is to search for signatures of a phenomenon predicted by perturbative quantum chromodynamics (pQCD) known as Color Transparency (CT). In this experiment the nuclear transparency of pions is extracted by using the ratio of semi-exclusive pion electroproduction from nuclear targets to the same from a hydrogen target. This method relies on the assumption that the reaction mechanism of electropion production from hydrogen is similar to the quasi-free eletropion production from nuclear targets. This assumption can tested by performing a Longitudinal-Transverse (L-T) separation of the pion electroproduction cross section and comparing the separated cross sections from hydrogen to that from heavier targets. In order to perform an L-T separation, data were collected at forward and backward electron angles at fixed momentum transfer squared ($Q^2$), for $Q^2$=2.15 and 4.0 $GeV^2/c^2$, which were chosen to fall within the $Q^2$ range over which the nuclear transparency is extracted. The extracted longitudinal and transverse cross sections at the two $Q^2$ settings from hydrogen, deuterium, carbon and copper targets will be presented.