The energy dependence of the multiplicity moments at the LHC

Abstract

In this work, from the experimental data we evaluate the first C-moments of the multiplicity distributions recently measured in proton-proton collisions at the LHC and compare them with the predictions of two models: the Kharzeev-Levin model and the Bialas-Praszalowicz model. We divide the data into three sets according to their phase space coverage: I: $p_T>100$ MeV and $|\eta |<0.5$; II: $p_T>100$ MeV and $|\eta |<2.4$ and II: $p_T>500$ MeV and $|\eta |<2.4$. The mean multiplicity grows with the energy according to a power law and the power is different for each set. The $C_n$ moments grow continuously with the energy, slowly in set I and faster in the other sets. Except for KL in set II, both models reproduce the main features of the data. The negative binomial parameter $k$ decreases continuously with the energy and there is no sign of change in this behavior.

Comments: 7 pages, 3 figures