CLAS physics database search results Measurement E159M571 E1-6 V. Burkert 2001 theta(pi+) dsigma/d(−cos(theta_pip)) Stat. error deg mcb/rad mcb/rad 9 1.05131 0.225797 27 1.7665 0.300814 45 1.94587 0.310474 63 1.70729 0.251362 81 2.07232 0.295787 99 2.17528 0.309272 117 1.8695 0.264866 135 1.62344 0.409933 153 1.06088 0.661648 171 1.33331 0.966239