A hydrodynamic model for hadron production ine +−e − annihilation

We consider hadron production ine ⁺-e ^? annihilation within the framework of a hydrodynamic model. The two key assumptions in the moddel are (i) the initial shape of a Lorentz-contracted disc for the hadronic fireball, with the jet axis providing the necessary longitudinal direction and (ii) the criterion of a critical size of hadronic dimension for the expanding fireball to break up into finalstate particles. Experimental data on charged multiplicity, inclusive distributions, dispersions and particle spectra upto the highest centre-of-mass energy, presently accessible in colliding-beam machines, are explained satisfactorily with only three energy-independent parameters. The present analysis brings out the similarity in the mechanism for hadron production inp-p collision ande ⁺-e ^? annihilation and attributes the apparent differences to the presence of leading-particle effect in the former process.