Micro-canonical pentaquark production in e+e− and pp collisions

The existence of pentaquarks became questionable, because the Θ+ peak is observed in some p+p collisions, but not in e+e− annihilations. People think initial baryon number is necessary to produce pentaquarks. In this paper, we estimate and compare the production of Θ+(1540) and Ξ−−(1860) in e+e− and pp collisions at different energies using Fermi statistical model as originally proposed in its microcanonical form. We find that both Θ+(1540) and Ξ−−(1860) yield more in e+e− at LEP energies than in pp collisions at SPS and RHIC energies, if pentaquarks do exist. Initial baryon number is not necessary for pentaquark production.