CLAS physics database search results Measurement E18M6 E89-004 R. A. Schumacher 2005 cos(theta) Cz Data errors dimensionless dimensionless dimensionless -0.75 0.974 0.426 -0.55 1.002 0.205 -0.35 0.762 0.14 -0.15 0.848 0.113 0.05 0.779 0.102 0.25 0.983 0.088 0.45 0.905 0.087 0.65 1.021 0.077 0.85 1.001 0.1