CLAS physics database search results Measurement E159M589 E1-6 V. Burkert 2001 theta(pi+) dsigma/d(−cos(theta_pip)) Data errors deg mcb/rad mcb/rad 9 1.70592 0.342571 27 1.75562 0.301776 45 1.64809 0.274897 63 1.67051 0.251138 81 1.67447 0.254539 99 1.84651 0.265116 117 1.87529 0.284103 135 1.51047 0.401626 153 1.08627 0.709364 171 1.2407 0.94078