Charge separation measurements in $p$($d$)+Au and Au+Au collisions; implications for the chiral magnetic effect

Abstract

Charge separation ($\Delta S$) measurements, obtained relative to the $2^{\mathrm{nd}}$-order (${\Psi }_2$) and $3^{\mathrm{rd}}$-order (${\Psi }_3$) event planes with a new charge-sensitive correlator $R_{{\Psi }_m}(\Delta S)$, are presented for $p$($d$)+Au and Au+Au collisions at $\sqrt{s_{NN}}=200$~GeV. The correlator, which is sensitive to the hypothesized Chiral Magnetic Effect (CME), show the expected patterns of background-driven charge separation for the measurements relative to ${\Psi }_3$ and those relative to ${\Psi }_2$ for the $p$($d$)+Au systems. By contrast, the Au+Au measurements relative to ${\Psi }_2$, show event-shape-independent $R_{{\Psi }_2}(\Delta S)$ distributions consistent with a CME-driven charge separation, quantified by widths having an inverse relationship to the Fourier dipole coefficient ${\tilde{a}}_1$, which evaluates the CME. The extracted values of these widths and their dependencies on centrality and event-shape give new constraints for possible CME-driven charge separation in relativistic heavy-ion collisions.

Comments: It is identified that results of the R_Psi3(Delta-S) correlator are invalid because of a programming error; no such error has been identified in the R_Psi2(Delta-S). AMPT results in Fig. 1(a) are improperly constructed and thus cannot be used to compare with the data. The manuscript is withdrawn from journal consideration; accordingly, the authors withdraw all conclusions of the manuscript