Rapid change of multiplicity fluctuations in system size dependence at SPS energies

TL;DR

This paper reports on the observed rapid change in multiplicity fluctuations across different collision systems at SPS energies, highlighting a significant drop from Be+Be to Ar+Sc collisions and discussing the effects of volume fluctuations.

Contribution

It provides new experimental results on multiplicity fluctuations in various collision systems and compares them with EPOS simulations, emphasizing the system size dependence at SPS energies.

Findings

Multiplicity fluctuations are stable from p+p to Be+Be

A dramatic drop in fluctuations occurs from Be+Be to Ar+Sc

Volume fluctuations influence the fluctuation measurements

Abstract

Recent preliminary results on multiplicity fluctuations in p+p, Be+Be and Ar+Sc collisions from the NA61/SHINE collaboration are presented. The scaled variance of charged hadron multiplicity changes little when going from p+p to Be+Be collisions and drops dramatically from Be+Be to Ar+Sc interactions. The centrality selection procedure and the influence of volume fluctuations are discussed. Comparisons with the EPOS event generator are shown.