BUSKULIC, D (reprint author), CNRS,INST NATL PHYS NUCL PHYS PARTICLES,PHYS PARTICULES LAB,F-74019 ANNECY LE VIEUX,FRANCE.
The decays eta --> gammagamma and eta' --> etapi+pi- have been observed in hadronic decays of the Z produced at LEP. The fragmentation functions of both the eta and eta' have been measured. The measured multiplicities for x > 0.1 are 0.298 +/- 0.023 +/- 0.021 and 0.068 +/- 0.018 +/- 0.016 for eta and eta' respectively. While the fragmentation function for the eta is fairly well described by the JETSET Monte Carlo, it is found that the production rate of the eta' is a factor of four less than the corresponding prediction.