Higher moments of multiplicity fluctuations in a hadron-resonance gas with exact conservation laws

TL;DR

This paper investigates higher moments of hadron multiplicity fluctuations in nucleus-nucleus collisions using a canonical ensemble approach, emphasizing exact conservation laws and their impact on fluctuation measurements at various collider energies.

Contribution

It introduces a comprehensive calculation of higher-order moments of multiplicity fluctuations with exact conservation laws in the hadron-resonance gas model, extending previous work to include multiple conserved charges and different energies.

Findings

Exact conservation laws significantly affect fluctuation moments.

Analytical expressions derived for simplified models with one conserved charge.

Calculated moments products for net-proton, net-kaon, and net-charge distributions at RHIC.

Abstract

Higher moments of multiplicity fluctuations of hadrons produced in central nucleus-nucleus collisions are studied within the hadron-resonance gas model in the canonical ensemble. Exact conservation of three charges, baryon number, electric charge, and strangeness, is enforced in the large volume limit. Moments up to the forth order of various particles are calculated at SPS, RHIC and LHC energies. The asymptotic fluctuations within a simplified model with only one conserved charge in the canonical ensemble are discussed where simple analytical expressions for moments of multiplicity distributions can be obtained. Moments products of net-proton, net-kaon, and net-charge distributions in Au + Au collisions at RHIC energies are calculated. The pseudo-rapidity coverage dependence of net-charge fluctuation is discussed.