Charge separation effect in relativistic heavy ion collisions

In this paper, we discuss alternative means of measuring the possible presence of local parity violation in relativistic heavy ion collisions. We focus on the phenomenon of charge separation and introduce the charged dipole vector Q̂₁^c, which will measure the charge separation on an event-by-event basis. Using Monte Carlo events, we demonstrate the method and its discriminating power. In particular we show that such an analysis will reveal the strength of the charge separation effect and its azimuthal correlation with the reaction plane. We further show that our proposed method may be able to distinguish between the actual charge separation effect and effects due to certain two-particle correlations. The connection to present measurements based on particle correlations is discussed.