Exotic State Searches at the SPring-8: Observation of a Pentaquark State   Theta^+ Baryon
  A narrow resonance peak was observed at 1.54 +/- 0.01 GeV as an exotic baryon with strangeness S = +1 in the gamma + n going to K^+ + K^- + n reaction on Carbon. The new state have a width smaller than 0.025 GeV and a Gaussian significance of 4.6 sigma. It can not be interpreted as three quark state and is consistent with the lightest member of an antidecuplet of baryons predicted by the chiral soliton model. 
Yuji Ohashi (on behalf of the LEPS collaboration)