The energy dependence of the multiplicity moments at the LHC

TL;DR

This paper analyzes the energy dependence of multiplicity moments in proton-proton collisions at the LHC, comparing experimental data with two theoretical models across different phase space regions.

Contribution

It evaluates the first C-moments of multiplicity distributions at the LHC and compares them with predictions from the Kharzeev-Levin and Bialas-Praszalowicz models.

Findings

Mean multiplicity follows a power law with energy, with different exponents for each phase space set.

C_n moments increase with energy, more rapidly in certain phase space regions.

Most model predictions align with data, except for the KL model in set II.

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.