Fluctuations of charge separation perpendicular to the event plane and local parity violation in sNN=200 GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider
Previous experimental results based on data (\sim${}15\ifmmode\times\else\texttimes\fi{}{10}^{6}events)collectedbytheSTARdetectorattheBNLRelativisticHeavyIonCollidersuggestevent−by−eventcharge−separationfluctuationsperpendiculartotheeventplaneinnoncentralheavy−ioncollisions.Herewepresentthecorrelatorpreviouslyusedsplitintoitstwocomponentpartstorevealcorrelationsparallelandperpendiculartotheeventplane.Theresultsarefromahigh−statistics200−GeVAu+Aucollisionsdataset(57\ifmmode\times\else\texttimes\fi{}{10}^{6}events)collectedbytheSTARexperiment.Weexplicitlycountunitsofchargeseparationfromwhichwefindclearevidenceformorecharge−separationfluctuationsperpendicularthanparalleltotheeventplane.Wealsoemployamodifiedcorrelatortostudythepossible\mathcal{P}−evenbackgroundinsame−andopposite−chargecorrelations,andfindthatthe\mathcal{P}$-even background may largely be explained by momentum conservation and collective motion.