Statistical model analysis of multiparticle correlations in e^+e^- annihilation

Abstract

A new statistical model for multiparticle production in $e^+e^-$ annihilation is proposed based on the idea of the longitudinal phase space with limited transverse momentum. The longitudinal rapidity space is divided into cells of equal size in order to take into account the Bose-Einstein correlations(BEC) with a finite correlation length $δy$. The maximum entropy method is used to determine the probability distributions of the final state pions (or $ρ$ mesons) for a given mean multiplicity, mean transverse momentum and mean total energy. Event simulation based on our model is performed in two extreme cases, a $π$-model and a $ρ$-model. The $π$-model assumes that only pions are produced directly. On the other hand, the $ρ$-model assumes that only $ρ$ mesons are produced directly and they decay into pions. A good overall fit to experimental data from PETRA to LEP energy regions is obtained for $δy$ ranging from 0.6 to 1.2 in the $π$-model. We found that the BEC plays a very important role to reproduce various correlation data. In some correlation data, resonance effect and conservation laws are also important.