Energy dependence of fluctuations in central Pb+Pb collisions from NA49 at the CERN SPS

TL;DR

This study analyzes fluctuations in central Pb+Pb collisions across a range of energies at CERN SPS, finding no signs of critical phenomena in multiplicity or transverse momentum fluctuations.

Contribution

It provides comprehensive fluctuation measurements over the entire SPS energy range, highlighting the energy dependence of multiplicity variance and the stability of transverse momentum fluctuations.

Findings

Multiplicity fluctuations decrease with energy.

Transverse momentum fluctuations remain small and energy-independent.

No evidence of the critical point in the analyzed fluctuations.

Abstract

The latest NA49 results on fluctuations of multiplicity and average transverse-momentum analyzed on an event-by-event basis are presented for central Pb+Pb interactions over the whole SPS energy range (20A - 158A GeV). The scaled variance of the multiplicity distribution decreases with collision energy whereas the $\Phi_{p_{T}}$ measure of $<p_T>$ fluctuations is small and independent of collision energy. Thus in central Pb+Pb collisions these fluctuations do not show an indication of the critical point of strongly interacting matter.