CLAS physics database search results Measurement E159M21 E1-6 V. Burkert 2001 theta(pi-) dsigma/d(−cos(theta_pim)) Data errors deg mcb/rad mcb/rad 9 2.1037 0.499767 27 1.01037 0.208387 45 1.08027 0.197976 63 1.133 0.196934 81 0.912128 0.162652 99 1.00729 0.187957 117 1.06093 0.184614 135 0.914983 0.168978 153 1.104 0.218833 171 1.15891 0.334451