Search for Pentaquarks in the Hadronic Decays of the Z Boson with the DELPHI Detector at LEP

Recent evidence for pentaquark states has been published, in particular for a strange pentaquark Θ+(1540), for a double‐strange state called Ⅺ(1862)−− and for a charmed state Θc(3100)0. Such states should be produced in e+e− annihilations in Z decays. In this paper a search for pentaquarks using the DELPHI detector is described. Preliminary upper limits at 95% C.L. are set on the production rates per Z decay of such particles and their charge‐conjugate state.