First-time measurement of the Koba-Nielsen-Olesen-like scaling of jet multiplicities in pp collisions at √s = 13 TeV with ALICE

One of the most influential contributions to the analysis of event multiplicity distributions is the Koba-Nielsen-Olesen (KNO) scaling hypothesis. It states that for very high energies the probability distributions P_n for detecting n final state particles exhibit a scaling law, i.e. the event multiplicity distributions can all be collapsed onto a universal scaling curve. Neither the origin of the KNO scaling, nor the mechanism that violates it is completely understood yet, although several scenarios have been proposed. Similarly to the observed deviations from Bjorken scaling in deep inelastic scattering processes, violation of the KNO scaling is an indication of the presence of complex dynamics in the underlying mechanisms of particle production.

Recent phenomenological studies based on proton--proton collisions found a KNO-like scaling within jets and concluded that the KNO scaling is violated by processes outside the jet development such as single and double-parton scatterings or softer multiple-parton interactions. This contribution presents a first-time measurement of the KNO-like scaling within jets in proton--proton collisions at √s = 13 TeV using ALICE data. The jet multiplicity distributions are scaled onto a universal scaling curve and the fulfillment of the scaling is quantified by calculating the statistical moments of the distributions. This measurement marks a significant milestone in validating the KNO-like scaling in experimental data and helps differentiate between certain fragmentation models.