Search for d^* Dibaryon by Double-radiative Capture on Pionic Deuterium
  We report a search for d^* dibaryon production by double-radiative capture on pionic deuterium. The experiment was conducted at the TRIUMF cyclotron using the RMC cylindrical pair spectrometer, and detected gamma-ray coincidences following pion stops in liquid deuterium. We found no evidence for narrow dibaryons, and obtained a branching ratio upper limit, BR < 6.7 times 10^{-6} (90% C.L.), for narrow d^* production in the mass range from 1920 to 1980 MeV.   Replaced with Physics Letter B accepted version and corrected normalization. 
P.A. Zolnierczuk (University of Kentucky), T.P. Gorringe (University   of Kentucky), M.D. Hasinoff (University of British Co...