Particle Production In Ee Annihilation At 29 Gev PDF Download

This paper presents the charged particle multiplicity distributions for ee− annihilation at .sqrt.s = 29 GeV measured in the High Resolution Spectrometer. The data, which correspond to an integrated luminosity of 185 pb−1, were obtained at the ee− storage ring PEP. The techniques used to obtain the original distributions from the observed prong numbers are discussed. The multiplicity distribution of the charged particles with a two jet selection has a mean value Nch = 13.02 +- 0.03 +- 0.5; and a dispersion D = 3.84 +- 0.02 +- 0.1. The mean multiplicity increases with the event sphericity. No correlation is observed between the multiplicities in the two jets that characterize most of the events. For the single jets a value of D = 2.71 +- 0.02 +- 0.06 is measured which gives further support the idea of independent jet fragmentation. When compared with e+e− data at other energies, the multiplicity distributions exhibit the scaling behavior in the mean first suggested by Koba, Nielsen and Olsen (KNO). The KNO distribution in the central rapidity interval is broader than that for the whole rapidity span and agrees well with the generalized Bose-Einstein formula for three independent sources. 17 refs., 14 figs.