A measurement of semi inclusive deep inelastic scattering pion asymmetries to test independent fragmentation

Semi-inclusive deep inelastic scattering (SIDIS) experiments may be used to identify the flavor of the quark that participates in the scattering process. Semi-inclusive scattering is defined as an electron scattering experiment in which the scattered electron and one hadron are detected in the final state. Experiments at Jefferson Lab have used longitudinally polarized electron beams to probe longitudinally polarized Hydrogen (15NH3) and Deuterium (15ND3) targets to investigate the quark's contribution to the properties of a nucleon. This thesis reports a measurement of SIDIS pion asymmetries using the CEBAF Large Acceptance Spectrometer (CLAS) at Thomas Jefferson National Laboratory. The incident electron's energy was 4.2 GeV and covered a kinematic region where the struck quark carries at least 30% of the nucleons total momentum (xB ≥ 0.3). The electrons scatter mostly from valence quarks in this kinematic region allowing measurements which are less sensitive to the ocean of quark-antiquark pairs that are also inside a nucleon.