  Experimental results of the SPHINX Collaboration on studying proton
diffractive production processes are presented. Evidences for new baryon states
with masses >1.8 GeV were obtained in hyperon-kaon effective mass spectra in
several reactions. New data for the diffractive reaction p+N->[Sigma0 K+]+N at
Ep=70 GeV were obtained with partially upgraded SPHINX setup. The data are in a
good agreement with the results of our previous study of this reaction. In the
mass spectrum M(Sigma0 K+) a structure at the threshold region with a mass
about 1800 MeV and a distinct X(2000) peak with M=1989+/-6 MeV and
Gamma=91+/-20 MeV are observed. Unusual features of the massive X(2000) state
(narrow decay width, anomalously large branching ratio for the decay channel
with strange particle emission) make it a serious candidate for a cryptoexotic
pentaquark baryon with hidden strangeness |qqqs sbar>. We also present new
results on the narrow threshold structure X(1810) with M=1807+/-7 MeV and
Gamma=62+/-19 MeV which is produced in the region of very small pt**2<0.01
GeV**2. The possibility of the Coulomb production mechanism for X(1810) is
discussed.
