CLAS physics database search results Measurement E159M459 E1-6 V. Burkert 2001 psi(pi-) dsigma/dpsi_pim Data errors deg mcb/rad mcb/rad 30 0.156433 0.0296798 90 0.240149 0.033588 150 0.308644 0.0558281 210 0.308382 0.046727 270 0.222134 0.0314765 330 0.169106 0.0312104