Measuring charge fluctuations in high-energy nuclear collisions

Abstract

Various measures of charge fluctuations in heavy-ion collisions are discussed. Advantages of the Phi-measure are demonstrated and its relation to other fluctuation measures is established. To get the relation, Phi is expressed through the moments of multiplicity distribution. We study how the measures act in the case of a `background' model which represents the classical hadron gas in equilibrium. The model assumes statistical particle production constrained by charge conservation. It also takes into account both the effect of incomplete experimental apparatus acceptance and that of tracking inefficiency. The model is shown to approximately agree with the PHENIX and preliminary STAR data on the electric charge fluctuations. Finally, `background-free' measures are discussed.

12 pages, 6 figures, numerous but minor changes, Phys. Rev. C in print

References in corpus (7)

• Charged particle densities from Au+Au collisions at sqrt{s_{NN}}=130 GeV
• Baryon Fluctuations and the QCD Phase Transition
• Baryon Number Fluctuation and the Quark-Gluon Plasma
• Acceptance Dependence of Fluctuation in Particle Multiplicity
• Charge fluctuations in a final state with QGP
• Charged Particle Fluctuation as Signal of the Dynamics in Heavy Ion Processes
• Influence of statistical fluctuations on $K/\pi$ ratios in relativistic heavy ion collisions

Cited by in corpus (11)

• Multiplicity fluctuations in Au+Au collisions at $\sqrt{s_{NN}}=130$ GeV
• Global baryon number conservation encoded in net-proton fluctuations measured in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV
• Beam-Energy and System-Size Dependence of Dynamical Net Charge Fluctuations
• Electric charge fluctuations in central Pb+Pb collisions at 20, 30, 40, 80 and 158 AGeV
• Multiplicity fluctuations in the hadron gas with exact conservation laws
• Possible Resolutions of the D-Paradox
• Baryon Number and Electric Charge Fluctuations in Pb+Pb Collisions at SPS energies
• Higher Moments of Net-Baryon Distribution as Probes of QCD Critical Point
• Boost Invariance and Multiplicity Dependence of the Charge Balance Functionin ${\pi }^{+}p$ and $K^{+}p$ Collisions at $\sqrt{s}=22$ GeV/c
• Statistical moments in superposition models and strongly intensive measures
• Charge Fluctuations in $π^{+}\rp$ and $\rK^{+}\rp$ Collisions at 250 GeV/$c$