High Statistics Search for the Theta+(1.54) Pentaquark State
  We have searched for Theta+(1.54) -> K0,p decays using data from the 1999 run of the HyperCP experiment at Fermilab. We see no evidence for a narrow peak in the K0,p mass distribution near 1.54 GeV/c among 106,000 K0,p candidates, and obtain an upper limit for the fraction of Theta+(1.54) to K0,p candidates of <0.3% at 90% confidence. 
M.J. Longo, R.A. Burnstein, A. Chakravorty, Y.C. Chen, W.S.Choong, K.   Clark, E.C. Dukes, C. Durandet, J. Felix, Y. Fu, G. ...