Upper limits for the photoproduction cross section for the Phi--(1860)   pentaquark state off the deuteron
  We searched for the Phi--(1860) pentaquark in the photoproduction process off the deuteron in the Xi- pi- decay channel using CLAS. The invariant mass spectrum of the Xi- pi- system does not indicate any statistically significant enhancement near the reported mass M = 1.860 GeV. The statistical analysis of the sideband-subtracted mass spectrum yields a 90% confidence level upper limit of 0.7 nb for the photoproduction cross section of Phi--(1860) with a consecutive decay into Xi- pi- in the photon energy range 4.5 GeV < Egamma < 5.5 GeV. 
H. Egiyan, J. Langheinrich, R.W. Gothe, L. Graham, M. Holtrop, H. Lu,   P. Mattione, G. Mutchler, K. Park, E.S. Smith, S. St...
nucl-ex