Entropy and mean multiplicity from dipole models in the high energy limit

TL;DR

This paper investigates dipole models in high energy physics, proposing entropy as a universal observable related to multiplicity, and finds the generalized model better fits proton-proton collision data.

Contribution

It introduces entropy as a universal measure linked to multiplicity and compares model predictions to experimental data, favoring the generalized dipole model.

Findings

The generalized dipole model fits proton-proton data better than the 1D Mueller model.

Entropy is proposed as a universal function of the logarithm of average multiplicity.

Model parameters are determined by fitting to measured charged particle distributions.

Abstract

The 1D Mueller dipole model, its high energy limit, and its generalization were investigated. To address the ambiguity stemming from different definitions of the pseudorapidity ranges in experimental measurements, we propose the entropy as the function of the logarithm of the average multiplicity, $S(\ln\langle n\rangle$, as a universal observable. From the solutions of the models, we calculate both the entropy and the average charged particle multiplicity and compare to data measured in proton-proton collisions. We obtained these quantities directly from the measured charged particle multiplicity distributions and determine the model parameters via fits. We find that the generalized dipole model provides a significantly better description of the data than the 1D Mueller model.