---
abstract: 'The multiplicity fluctuations are studied in the van der Waals excluded volume hadron-resonance gas model. The calculations are done in the grand canonical ensemble within the Boltzmann statistics approximation. The scaled variances for positive, negative and all charged hadrons are calculated along the chemical freeze-out line of nucleus-nucleus collisions at different collision energies. The multiplicity fluctuations are found to be suppressed in the van der Waals gas. The numerical calculations are presented for two values of hard-core hadron radius, $r=0.3$ fm and 0.5 fm, as well as for the upper limit of the excluded volume suppression effects.'
author:
- 'M.I. Gorenstein'
- 'M. Hauer'
- 'D.O. Nikolajenko'
title: |
     Particle number fluctuations in nuclear collisions\
    within excluded volume hadron gas model
---

Introduction
============

During last decades statistical models of strong interactions have served as an important tool to investigate high energy nuclear collisions. The main object of the study have been the mean multiplicities of produced hadrons (see e.g. Refs. [@FOC; @FOP; @pbm]). Only recently, due to a rapid development of experimental techniques, first measurements of fluctuations of particle multiplicities [@fluc-mult] and transverse momenta [@fluc-pT] were performed. The study of event-by-event fluctuations in nucleus-nucleus collisions (see e.g., 