CLAS physics database search results Measurement E159M643 E1-6 V. Burkert 2001 theta(pi+) dsigma/d(−cos(theta_pip)) Data errors deg mcb/rad mcb/rad 9 1.53071 0.29307 27 1.6337 0.280665 45 1.44377 0.24797 63 1.67397 0.263048 81 1.3884 0.214222 99 1.56612 0.23296 117 1.61494 0.254959 135 1.60346 0.389989 153 1.33877 0.911168 171 1.22424 0.927431