Search for the decay B0 -> phi gamma
  We have searched for the decay B0 -> phi gamma using the full Belle data set of 772 x 10^6 BBbar pairs collected at the Upsilon(4S) resonance with the Belle detector at the KEKB e+e- collider. No signal is observed, and we set an upper limit on the branching fraction of B(B0 -> phi gamma) < 1.0 x 10^{-7} at 90% confidence level. This is the most stringent limit on this decay mode to date. 
Belle Collaboration: Z. King, B. Pal, A. J. Schwartz, I. Adachi, H.   Aihara, S. Al Said, D. M. Asner, H. Atmacan, T. Aushev...
hep-ex