CLAS physics database search results Measurement E18M31 E89-004 R. A. Schumacher 2005 cos(theta) Cx Data errors dimensionless dimensionless dimensionless -0.75 -0.393 0.432 -0.55 -0.007 0.42 -0.35 -0.938 0.466 -0.15 -0.188 0.406 0.05 -0.521 0.403 0.25 -0.289 0.401 0.45 -0.426 0.189 0.65 -0.258 0.126 0.85 -0.45 0.114