CLAS physics database search results Measurement E216M166 CLAS12 Run Group A Krishna Chandra 2018 psi(pi-) dsigma/dpsi_pim Stat. error Syst. error deg mcbn/rad mcbn/rad mcbn/rad 18 0.413613 0.0211248 0.06311388 54 0.469269 0.0273766 0.04439892 90 0.501057 0.0228885 0.03887448 126 0.529284 0.0181976 0.04179887 162 0.550492 0.0140086 0.04148684 198 0.543132 0.0151335 0.04271431 234 0.523442 0.0170442 0.03852199 270 0.47913 0.0150187 0.0370727 306 0.418256 0.017051 0.06347938 342 0.433777 0.0283319 0.062091