Net Charge Fluctuations and Chemical Freez-out Conditions

Event by event Net Charge Fluctuations

We present analyses of event-by-event dynamical net charge fluctuations measured in130 and 200 GeV Au Au collisions with the STAR detector. The dynamical net charge fluctuations are evaluated using the ν+−,dyn observable. Dynamical fluctuations measured in Au Au collisions at 130 and 200 GeV are finite, and exceed charge conservation limits. They deviate from a perfect 1/N scaling and provide a...

Net-charge probability distributions in heavy ion collisions at chemical freeze-out

The distributions for strangeness, electric charge and baryon number are explored in heavy ion collisions within the hadron resonance gas model. The proximity of the freeze-out curve to the phase boundary indicates that the QCD phase transition and its related critical properties should be observable in heavy ion collisions. However, an experimental verification of a phase change in a medium cr...

2 00 4 Net Charge and Isospin Fluctuations in the World of Elementary Particles

Charge and isospin event-by-event fluctuations in high-energy pp-collisions are predicted within the Unitary Eikonal Model (UEM), in particular the fluctuation patterns of the ratios of charged-to-charged and neutral-to-charged pions. These fluctuations are found to be sensitive to the presence of unstable resonances, such as ρ and ω mesons.We predict that the charge-fluctuation observable D U ...

Beam-energy and system-size dependence of dynamical net charge fluctuations

Beam-Energy and System-Size Dependence of Dynamical Net Charge Fluctuations

We present measurements of net charge fluctuations in Au + Au collisions at √ sNN = 19.6, 62.4, 130, and 200 GeV, Cu + Cu collisions at √ sNN = 62.4, 200 GeV, and p + p collisions at √ s = 200 GeV using the net charge dynamical fluctuations measure ν+−,dyn. The dynamical fluctuations are non-zero at all energies and exhibit a rather modest dependence on beam energy. We find that at a given ener...