CLAS physics database search results Measurement E216M553 CLAS12 Run Group A Krishna Chandra 2018 psi(pi-) dsigma/dpsi_pim Stat. error Syst. error deg mcbn/rad mcbn/rad mcbn/rad 18 0.178662 0.0172144 0.03241979 54 0.200087 0.0131856 0.01992795 90 0.228925 0.0116317 0.01697216 126 0.249979 0.00989814 0.01844262 162 0.256954 0.0116245 0.02127567 198 0.249479 0.00909032 0.01947674 234 0.241011 0.00997933 0.01908925 270 0.225284 0.0100788 0.01786896 306 0.259895 0.0486837 0.04568236 342 0.199543 0.0202156 0.0288818