Statistical hadronisation model and transverse momentum spectra of hadrons in high energy collisions

Abstract

A detailed analysis of transverse momentum spectra of several identified hadrons in high energy collisions within the canonical framework of the statistical model of hadronisation is performed. The study of particle momentum spectra requires an extension of the statistical model formalism used to handle particle multiplicities, which is described in detail starting from a microcanonical treatment of single hadronising clusters. Also, a new treatment of extra strangeness suppression is presented which is based on the enforcement of fixed numbers of ssbar pairs in the primary hadrons. The considered centre-of-mass energies range from ~ 10 to 30 GeV in hadronic collisions (pion-p, pp and Kp) and from ~ 15 to 35 GeV in e+e- collisions. The effect of the decay chain following hadron generation is accurately and exhaustively taken into account by a newly proposed numerical method. The exact p_T conservation at low energy and the increasing hard parton emission at high energy bound the validity of the presently taken approach within a limited centre-of-mass energy range. However, within this region, a clear consistency is found between the temperature parameter extracted from the present analysis and that obtained from fits to average hadron multiplicities in the same collision systems. This finding indicates that in the hadronisation process the production of different particle species and their momentum spectra are two closely related phenomena governed by one parameter.