Observation of a narrow structure in p(gamma,K_s)X via interference with   phi-meson production
  We report observation of a narrow peak structure at ~1.54 GeV with a Gaussian width sigma=6 MeV in the missing of K_s in the reaction gamma+p = pK_sK_L. The observed structure may be due to the interference between a strange (or anti-strange) baryon resonance in the pK_L system and the phi(K_sK_L) photoproduction leading to the same final state. The statistical significance of the observed excess of events estimated as the log likelihood ratio of the resonant signal+background hypothesis and the phi-production based background only hypothesis corresponds to 5.3 sigma. 
M. J. Amaryan, G. Gavalian, C. Nepali, M. V. Polyakov, Ya. Azimov, W.   J. Briscoe, G. E. Dodge, C. E. Hyde, F. Klein, V. Ku...
hep-ex hep-ph nucl-ex