CLAS physics database search results Measurement E159M490 E1-6 V. Burkert 2001 theta(pi+) dsigma/d(−cos(theta_pip)) Data errors deg mcb/rad mcb/rad 9 0.720529 0.16892 27 1.48842 0.270539 45 1.08924 0.184159 63 1.05002 0.157498 81 1.02047 0.140417 99 1.12171 0.165356 117 1.30211 0.194741 135 0.869636 0.216656 153 0.571329 0.389024 171 0.523733 0.471531