CLAS physics database search results Measurement E19M17 E89-004 R. A. Schumacher 2005 cos(theta) Cx Data errors dimensionless dimensionless dimensionless -0.7 -1.268 0.48 -0.4 -1.606 0.43 -0.1 -0.629 0.294 0.2 -1.315 0.196 0.5 0.004 0.188 0.8 -0.185 0.216