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

We present measurements of net charge fluctuations in Au + Au collisions at √(s_NN) = 19.6, 62.4, 130, and 200 GeV, Cu + Cu collisions at √(s_NN) = 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 energy and collision system, net charge dynamical fluctuations violate 1/ N ch scaling, but display approximate 1/ N part scaling. We observe strong dependence of dynamical fluctuations on the azimuthal angular range and pseudorapidity widths.