Fluctuations of charge separation perpendicular to the event plane and local parity violation in √S[subscript NN] = 200 GeV Au + Au collisions at the BNL Relativistic Heavy Ion Collider

Previous experimental results based on data (similar to 15 x 10(6) events) collected by the STAR detectorat the BNL Relativistic Heavy Ion Collidersuggest event-by-event charge-separation fluctuations perpendicularto the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicularto the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57 x 10(6) events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicularthan parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion.