Multiplicities in ultrarelativistic proton-(anti)proton collisions and negative binomial distribution fits

Abstract

Likelihood ratio tests are performed for the hypothesis that charged-particle multiplicities measured in proton-(anti)proton collisions at $\sqrt{s}$ = 0.9 and 2.36 TeV are distributed according to the negative binomial form. Results indicate that the hypothesis should be rejected in the all cases of ALICE-LHC measurements in the limited pseudo-rapidity windows, whereas should be accepted in the corresponding cases of UA5 data. Possible explanations of that and of the disagreement with the least-squares fitting method are given.

Comments: 14 pages, clarified version, reference added. To appear in International Journal of Modern Physics A