Search for Pentaquarks with HERA-B
  A large data set of proton-nucleus collisions at sqrt(s) =41.6 GeV has been searched for Theta+ and Xi(1862) pentaquark candidates. In 2x10**8 inelastic events we find no evidence for narrow signals (sigma=5 MeV/c**2) in the Theta+ --> pK0s and Xi--(1862) --> Xi- pi- channels. Upper limits on production cross sections at mid-rapidity and on ratios of production cross sections to those of well established resonances are presented. 
Joachim Spengler (Max-Planck-Institut fuer Kernphysik, Heidelberg,   Germany)