2024/06/07 by Germano, G. R., Navarra, F. S., Wilk, G. +1
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)
paper · doi:10.48550/arxiv.2406.04856
In this work we study the multiplicity distributions (MDs) of charged particles within jets in proton-proton collisions, which were measured by the ATLAS collaboration in 2011, 2016 and 2019. The first data set refers to jets with lower transverse momenta (4 < pT < 40 GeV ) whereas the other two refer to higher pT jets (0.1 < pT < 2.5 TeV). We find that the first set shows no sign of KNO scaling whereas the higher pT sets gradually approach the scaling limit. In the first set the mean multiplicity as a function of pT can be well described by expressions derived from QCD with different approximation schemes. For higher (> 500 GeV) values of pT these expressions significantly overshoot the data. We show that the behavior of the MDs can be well represented by a Sub-Poisson distribution with energy dependent parameters. In the range 40 < pT < 100 GeV there is a transition from sub to super poissonian behavior and the MD evolves to a geometric distribution, which shows KNO scaling. In this way we fit the MDs in all transverse momentum intervals with one single expression. We discuss the implications of this phenomenological finding.