Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity ($\mathrm{\Delta }\eta$) between a high transverse momentum ($p_{\perp }$) trigger particle and two lower $p_{\perp }$ associated particles within azimuth $\mid$$\mathrm{\Delta }\varphi$$\mid$$<$0.7 in $\sqrt{s_{NN}}$ = 200 GeV $d$+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jet-like component and the ridge (long-range $\mathrm{\Delta }\eta$ correlation). The results indicate that the particles from the ridge are uncorrelated in $\mathrm{\Delta }\eta$ not only with the trigger particle but also between themselves event-by-event. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jet-like component.