QCD test with the momentum spectra and the second binomial moment R2 using e+e− data

Abstract

Experimental data on the shape of hadronic momentum spectra are compared to the context of calculations in modified leading log approximation (MLLA), under the assumption of local parton hadron duality (LPHD). Considered are the inclusive momentum spectra and charged particle distributions in the reaction e+e− → hadrons, using the experimental as well as the Monte Carlo data at center of mass energies up to 200 GeV. Values of the second binomial moment R2 obtained from the multiplicity distributions are also studied. Our results are compared with both experimental data from high and low energy e+e−, e−p, and pp experiments and QCD calculations in various theoretical approaches. In general, good agreement is found between the measurements and the corresponding QCD predictions. A quantitative check of LPHD + MLLA has been performed by extracting a value of the strong coupling constant from the corresponding distributions. Possible explanations for all these features will be presented in this paper.