CLAS physics database search results Measurement E19M27 E89-004 R. A. Schumacher 2005 cos(theta) Cx Data errors dimensionless dimensionless dimensionless -0.7 -1.474 1.238 -0.4 0.08 2.297 -0.1 -3.047 1.204 0.2 0.014 0.835 0.5 0.459 0.363 0.8 -0.49 0.315